Denial of service CVEs.

clnttcp_call() in lib/rpc/clnt_tcp.c in MIT Kerberos 5 (aka krb5) does not free the RPC reply verifier between retries, which allows remote attackers to cause a denial of service (memory leak in GSS-RPC client programs) by injecting RPC replies with mismatched XIDs or by triggering authentication retries.

Denial of service

The AUTH_GSSAPI handler in lib/rpc/svc_auth_gssapi.c in MIT Kerberos 5 (aka krb5) does not free decoded arguments on certain error paths, which allows remote attackers to cause a denial of service (memory exhaustion in kadmind) via crafted AUTH_GSSAPI_INIT requests that trigger authentication failures.

Denial of service

clean_client() in lib/rpc/svc_auth_gssapi.c in MIT Kerberos 5 (aka krb5) restarts its scan from the head of the client list after each removal, resulting in quadratic CPU cost. Remote attackers can cause a denial of service (CPU consumption in kadmind) by accumulating a large number of AUTH_GSSAPI client entries.

Denial of service

In JetBrains YouTrack before 2026.2.19728 the attachment size limit could be bypassed via AI assistant thread conversion

Denial of service

The GSS-RPC layer in MIT Kerberos 5 (aka krb5) does not enforce size limits on XDR-decoded data, which allows remote authenticated users to cause a denial of service (memory exhaustion or excessive CPU consumption in kadmind) via crafted RPC requests that trigger unbounded memory allocations during XDR decoding.

Denial of service

A flaw was found in the SAML 1.1 XML parsing logic of Keycloak, an open-source identity and access management solution. The issue occurs when the parser encounters unexpected elements within a security token's key information section, causing the processing thread to enter an infinite loop. An unauthenticated remote attacker could exploit this by sending specially crafted requests, leading to 100% CPU usage and a total denial of service that requires a server restart to resolve.

Denial of service Web app

The GSS-RPC transport layer in MIT Kerberos 5 (aka krb5) 1.4 and later does not release the previous authentication context when a client switches from an RPCSEC_GSS or AUTH_GSSAPI flavor to a non-GSS flavor on the same TCP connection. This allows remote attackers to cause a denial of service (memory exhaustion in kadmind) by repeatedly establishing and abandoning GSS authentication contexts.

Denial of service

xdr_krb5_tl_data() in lib/kadm5/kadm_rpc_xdr.c in MIT Kerberos 5 (aka krb5) does not free partially decoded data on failure, which allows remote authenticated users to cause a denial of service (memory leak in kadmind) via crafted RPC requests that trigger a decode failure.

Denial of service

A flaw was found in the SAML XML processing component of Keycloak, an open-source identity and access management solution. The issue occurs when the server parses XML documents containing excessively long dateTime or duration values. Because these strings are not properly validated before processing, the XML parser consumes excessive CPU time. An unauthenticated remote attacker can exploit this by sending specially crafted SAML requests to the server, leading to high CPU utilization and a denial of service for all users.

Denial of service Library

The RPCSEC_GSS authentication routines in lib/rpc/authgss_prot.c in MIT Kerberos 5 (aka krb5) 1.4 and later do not free partially decoded buffers on failure, which allows remote attackers to cause a denial of service (memory leak in kadmind) via crafted RPCSEC_GSS messages.

Denial of service

A flaw was found in the SAML 1.1 assertion parser of Keycloak, a tool used for identity and access management. The issue occurs when the parser handles a specific element called AuthorityBinding within an authentication statement. Due to an incomplete fix for a previous vulnerability, the parser can enter an infinite loop that consumes all available memory, causing the entire Keycloak service to crash and become unavailable to users.

Denial of service Library

A flaw was found in the SAML implementation of Keycloak, an open-source identity and access management solution. The SAML Artifact Resolution and ECP SOAP endpoints do not properly limit the size or complexity of incoming XML requests. An unauthenticated remote attacker can exploit this by sending specially crafted, large XML messages that cause the server to consume excessive memory. This leads to the application running out of memory and crashing, resulting in a denial of service for all users.

Denial of service Web app

decode_sequence_of() in lib/krb5/asn.1/asn1_encode.c in MIT Kerberos 5 (aka krb5) 1.11 and later grows the decoded element array one entry at a time, which allows remote attackers to cause a denial of service (CPU consumption in the KDC) by sending an unauthenticated AS-REQ or TGS-REQ with a large number of elements in a SEQUENCE OF field over TCP.

Denial of service

The AUTH_GSSAPI handler in lib/rpc/svc_auth_gssapi.c in MIT Kerberos 5 (aka krb5) 1.5.2 and later allows remote attackers to cause a denial of service (memory exhaustion in kadmind) by sending repeated failed AUTH_GSSAPI_INIT requests. Each failed request allocates client state that is only freed after a 15-minute expiration timeout, allowing an attacker to accumulate memory faster than it is reclaimed.

Denial of service

Allocation of Resources Without Limits or Throttling vulnerability in Apache Axis2/Java. The JSON message builders, including the Gson, Moshi and HTTP/2 variants, buffered the entire request body with no size limit, so an unauthenticated caller could exhaust server memory with a large JSON request. Version 2.0.2 bounds JSON request bodies with the configurable jsonMaxRequestSize parameter. This issue affects Apache Axis2/Java: through 2.0.1. Users are recommended to upgrade to version 2.0.2, which fixes the issue.

Denial of service Server

Uncontrolled recursion in Apache ZooKeeper. The server serializes its data tree to a snapshot by recursing one stack frame per znode level, with no depth bound. A client permitted to create znodes (the default root ACL is open) can build a chain of nested znodes deep enough that taking a snapshot exhausts the JVM stack and kills the snapshot thread; sizes stay within jute.maxbuffer, so existing limits do not prevent it. This is a denial of service that becomes persistent: on restart the server rebuilds the deep tree from its transaction log and fails again while taking the startup snapshot, so it does not return to service, and recovery can entail data loss. The same log affects a leader and its followers, so it can spread across an ensemble. This issue affects Apache ZooKeeper 3.8.0 through 3.8.7 and 3.9.0 through 3.9.6. Users are recommended to upgrade to 3.8.8 or 3.9.7, which fix the issue. As a workaround, use ACLs and authentication to restrict znode creation rather than relying on the default open root ACL.

Denial of service Server

The Model Context Protocol TypeScript SDK provides TypeScript client and server implementations of the Model Context Protocol. From 1.3.0 until 1.32.0 in @modelcontextprotocol/sdk and from 2.0.0 until 2.3.0 in @modelcontextprotocol/server, HTTP servers did not enforce a limit on the number of array elements and object keys validated in one request. The affected surface is validation of HTTP requests containing arrays or object keys. The trigger is an array-element or object-key validation workload large enough to exhaust memory while remaining within the request size limit. A single request within the default 4 MiB limit can terminate the process with JavaScript heap exhaustion. No credentials are required unless the application authenticates before SDK processing. Tools accepting arrays or records carry the greatest risk. stdio-only servers do not expose the HTTP request path. Upgrading alone does not enable the new validation bound. Operators must configure both a tool-input element bound and an appropriate request body size limit. This issue is fixed in @modelcontextprotocol/sdk 1.32.0 and @modelcontextprotocol/server 2.3.0.

Denial of service Library

krb5_ktkdb_get_entry() in lib/kdb/keytab.c in MIT Kerberos 5 (aka krb5) 1.2.8 and later does not free decrypted key material when a post-decryption check fails, which allows remote attackers to cause a denial of service (memory leak in the KDC or kadmind) via requests that repeatedly trigger key decryption failures.

Denial of service

A flaw was found in the theme resource endpoint of Keycloak, an open-source identity and access management solution. The issue occurs because the server fails to validate theme names before using them as keys for an on-disk gzip cache. An unauthenticated attacker can exploit this by sending many requests with unique, fabricated theme names, leading to persistent disk space exhaustion that survives server restarts and causes service disruptions.

Denial of service Web app

A flaw was found in GStreamer's gst-plugins-bad package. A use of uninitialized memory vulnerability exists in the H.265 (HEVC) bitstream parser when processing Video Parameter Sets that declare more than one HRD (Hypothetical Reference Decoder) parameter set. A remote attacker could exploit this by providing a crafted H.265 media file or stream that, when processed by an application using GStreamer, causes unpredictable parser behavior and may crash the application. This can lead to a denial of service for any application using GStreamer to play back H.265 content.

Denial of service Library

Uncontrolled Resource Consumption in ServiceMultiEventHandler in Apache OFBiz 24.09 before 24.09.08 on all platforms allows a remote unauthenticated attacker to pin a server request thread for an attacker-chosen number of synchronous service dispatches, up to the signed-integer maximum, by submitting a single small HTTP request whose parameter names encode a row count via the "o" suffix used by multi-form submissions, because UtilHttp.getMultiFormRowCount derives that count from the largest such suffix with no upper bound and ServiceMultiEventHandler.invoke then loops that many times calling dispatcher.runSync, with the request-map for getFinAccountTransRunningTotalAndBalances reaching this handler with no authentication or CSRF requirement on a stock deployment. Users are recommended to upgrade to version 24.09.08, which fixes this issue.

Denial of service Web app Apache Ofbiz

FreeRDP before 3.32.2 contains a denial of service vulnerability in the NLA-enabled shadow server when a CredSSP TSRequest omits negoTokens. Unauthenticated attackers can send a crafted seven-byte TSRequest containing only the version field to trigger a fatal WINPR_ASSERT and abort the server process.

Denial of service Library Freerdp

JSON-java is a reference implementation of a JSON package in Java. From version 20150729 through 20260522, JSONTokener.nextSimpleValue can accumulate unbounded numeric tokens before JSONObject.stringToNumber passes them to BigInteger or BigDecimal conversion without a length limit. An application that parses attacker-controlled JSON or XML through JSONObject, JSONArray, or XML.toJSONObject can spend super-linear CPU time converting a sufficiently long numeric literal, blocking request-handling threads and causing denial of service. Strict mode and keep-strings settings in JSONParserConfiguration do not prevent the affected conversion path. Version 20260719 limits numeric conversion length.

Denial of service Library

BabelDOC from 0.3.61 before 0.7.0 contains a resource exhaustion vulnerability that allows remote attackers to exhaust CPU and memory by supplying unbounded bfrange and cidrange spans. Attackers can submit a crafted PDF whose embedded ToUnicode CMap declares a huge range, driving billions of loop iterations and stalling the translation worker.

Denial of service Device

Allocation of Resources Without Limits or Throttling vulnerability in ninenines cowboy allows an unauthenticated remote attacker to exhaust connection process memory over HTTP/1.1. Once a request has been received in full and its handler is still running, cowboy_http:parse/2 in src/cowboy_http.erl appends every further byte that arrives on the keep-alive connection to the connection buffer and returns to the receive loop without parsing it. The socket stays in active mode and no limit applies to this buffer: max_request_line_length, max_headers and the other parser limits only take effect once the handler returns and parsing resumes, and the only timer in this state is idle_timeout (default 60 seconds), which is reset on every received chunk. A client can therefore send an arbitrary amount of data on one connection for as long as the handler runs, and a few connections to an endpoint that holds requests open can drive the Erlang VM into out-of-memory conditions. This issue affects cowboy: from 2.18.0 before 2.21.0.

Denial of service Web app

Pillow is a Python imaging library. In versions 2.3.0 through 12.3.0, EPS rendering does not validate the scaled image dimensions before invoking Ghostscript. Applications that process untrusted EPS or PostScript files using an application-selected scale greater than one can incur excessive Ghostscript CPU and temporary disk consumption. In versions with decompression-bomb protection, the scaled output is checked only after Ghostscript has completed rendering, allowing resource consumption beyond the configured pixel limit. The amplification depends on the scale selected by the application, not an attacker-controlled scale value. This issue is fixed in version 13.0.0.

Denial of service Library Python Pillow

Sliver is a command and control framework. Prior to 1.7.6, an HTTP(S) listener using the PNG encoder accepts attacker-controlled PNG dimensions without an effective decoded-size or pixel limit in util/encoders/images.go, while the listener nonce space implemented in server/encoders/encoders.go is small enough to search remotely. An unauthenticated attacker who identifies a valid nonce can submit a highly compressed image to PNGEncoder.Decode, where it expands during png.Decode, exhausting server memory and causing a complete loss of availability. This vulnerability is fixed in 1.7.6.

Denial of service Server

Allocation of Resources Without Limits or Throttling in the multiRead request handler of Apache ZooKeeper allows a remote attacker to crash the server (denial of service) with a single small request. The multiRead handler places no limit on the number of bundled read operations or on the cumulative size of the response it builds in memory. Because each operation's result is fully materialized and retained before serialization, a request that is small on the wire — within the jute.maxbuffer limit — but that references a large znode many times can force the server to allocate far more heap than the request size implies, exhausting the JVM heap and terminating the server with an OutOfMemoryError. Neither jute.maxbuffer nor largeRequestMaxBytes prevents this, as both bound only the inbound request, not the response. This issue affects Apache ZooKeeper from 3.7.0 through 3.9.6. Users are recommended to upgrade to version 3.9.7, which enforces configurable limits on the multiRead operation count and cumulative response size.

Denial of service Server

IBM API Connect 10.0.8.0 through 10.0.8.12 and 12.1.0.0 through 12.1.1.2 could allow a remote authenticated attacker to cause a denial of service due to uncontrolled resource consumption. Certain requests can cause internal processing to stall, which could make the service unavailable.

Denial of service Server IBM Api Connect

The Symfony Yaml components Inline and Parser, parse some YAML documents inefficiently, so that a small crafted document can take disproportionately long to process, keeping a PHP process busy for seconds or minutes, potentially causing a denial of service in Symfony versions prior to 5.4.56, 6.x prior to 6.4.50, 7.x prior to 7.4.23, and 8.x prior to 8.1.11. The parser repeats work it has already done in several places. An embedded mapping in a flow sequence is parsed again for every scalar appended to it, and so are the collections nested in it, so the parse time grows exponentially with the nesting depth. The patterns matching mapping keys and tags scan a run of spaces once per character of the run, and each scalar of a flow collection is matched against a copy of the rest of the collection, so the parse time grows quadratically with the size of the input. Nested blocks are also copied at each nesting level, which consumes memory as well as time. A few other constructs, such as an empty sequence item followed by a blank line or an anchor named 0, trigger similar repeated work. Any code parsing untrusted YAML is affected, with the default flags. In Symfony 7.4 and later, that includes #[MapRequestPayload] when the Yaml component is installed and the endpoint does not restrict acceptFormat. A single unauthenticated request with a YAML content type keeps a PHP worker busy until max_execution_time. JSON documents are valid YAML, so a JSON payload sent with a YAML content type is enough for the flow collection case. In Symfony 6.4, #[MapRequestPayload] accepts YAML only when the application registers a yaml request format.

Denial of service Web app

Eclipse Langium versions 3.2.0 through 4.4.0 contain an inefficient algorithmic complexity issue (CWE-407) in the opt-in IndentationAwareTokenBuilder and IndentationAwareLexer. When producing DEDENT tokens, the token builder recomputes line numbers by re-scanning the entire preceding document text. A document whose indentation changes on most lines then takes quadratic time to tokenize. Because tokenization is synchronous, a crafted document of a few hundred kilobytes can block the Node.js event loop for tens of seconds. That causes a DoS for every user served by the same process. Languages built with the DefaultLexer and DefaultTokenBuilder are unaffected.

Denial of service

Pillow is a Python imaging library. In versions through 12.3.0, the libtiff TIFF encoder can pass arguments to  TIFFSetField()  that do not match libtiff’s definition of the corresponding tag. When an application saves attacker-controlled image metadata through this encoder, crafted tag values can cause invalid memory reads, copying process memory into the encoded output or crashing the process. Applications that return the encoded output to an attacker can disclose that memory. The issue is reachable when re-saving compressed TIFF images and through certain conversions that preserve EXIF metadata into compressed TIFF output. This vulnerability is fixed in version 13.0.0.

Denial of service Library Python Pillow

CGI versions before 5.00 for Perl allow denial of service via submitted values used as a regex for optgroup selection in scrolling_list. When rendering option groups, scrolling_list marks the selected options by interpolating each selected value, by default taken from the request parameters, unescaped into a substitution pattern. A client can make the request die with an invalid pattern, or tie up the process with one that backtracks heavily.

Denial of service Web app

CGI::Cookie versions from 4.67 before 5.00 for Perl allow denial of service via the client cookie expires value used as a regex in parse. CGI's cookie method reads the Cookie request header through parse, which interpolates the header's expires value unescaped into the substitution pattern that removes it from the cookie string. A client can make the request die with an invalid pattern, or tie up the process with one that backtracks catastrophically.

Denial of service

Allocation of Resources Without Limits or Throttling vulnerability in elixir-ecto ecto allows an unauthenticated remote attacker to exhaust memory in the application and in the database server by sending requests with distinct JSON keys or list lengths where the application interpolates them into json_extract_path/2, field[^key] or splice/1. Ecto caches prepared queries per repository in an ETS table with no size limit and no eviction. Interpolated JSON path elements become part of the query expression instead of its parameters, and splice/1 expands into one placeholder per element, so every distinct key or list length creates a new cache entry. With ecto_sql each entry is also a new prepared statement on the database connection that runs it. None of this memory is released until the processes restart. This issue affects ecto: from 3.4.0 before 3.14.3.

Denial of service Library

IBM ContextForge MCP Gateway 1.0.0 through 1.0.11 could allow a remote authenticated attacker to cause a denial of service due to improper slug normalization causing tool name collisions.

Denial of service IBM Contextforge

Improper handling of exceptional conditions in the quota subsystem of Apache ZooKeeper allows an attacker able to write under the /zookeeper/quota subtree — unauthenticated on default deployments, where that subtree is world-writable — to crash the server's critical request-processing thread and render the on-disk data directory permanently unbootable. This issue affects Apache ZooKeeper up to and including 3.9.6. Users are recommended to upgrade to version 3.8.8 or 3.9.7, which fixes the issue.

Denial of service Server

CGI versions from 4.71 before 5.00 for Perl allow denial of service via a plain string dereferenced as a symbolic reference in uploadInfo. uploadInfo dereferences its argument and calls its filename method without checking that it is an upload filehandle. A plain string naming a defined global variable, such as the parameter value from ?upload=0, is treated as a symbolic reference, and the method call on it dies.

Denial of service Web app

Urwid is a console user interface library for Python. Prior to 4.0.7, handle_short_request() in urwid/display/web.py performs unguarded character encoding on POST input and unguarded UTF-8 decoding on polling update socket output. A remote attacker who obtains a valid X-Urwid-ID session token can submit non-ASCII POST data that raises UnicodeEncodeError, while non-UTF-8 polling output raises UnicodeDecodeError, causing the CGI handler to return an error and terminate request processing. The POST exception path also leaves an opened file descriptor unclosed for the CGI process lifetime, so repeated requests can cause denial of service for the web display interface. This issue is fixed in version 4.0.7.

Denial of service Library

A length validation flaw in gdbserver's agent-expression parser allows an unauthenticated remote attacker to read uninitialized heap memory from the gdbserver process and cause a denial of service. Disclosed heap content includes addresses suitable for defeating ASLR in further exploitation.

Denial of service Device

Denial of Service via OOM vulnerability in Apache ActiveMQ, ActiveMQ Broker. An authenticated OpenWire client that sends a ConsumerInfo for a temporary queue/topic owned by another connection is rejected with InvalidDestinationException, but the rejected Subscription is left behind in the region's subscriptions map. Repeating the request leaks broker heap until OOM because the broker does not clean up the rejected subscriptions in the map. This issue affects Apache ActiveMQ: from 6.0.0 before 6.3.3, before 5.19.12; ActiveMQ Broker: from 6.0.0 before 6.3.3, before 5.19.12. Users are recommended to upgrade to version 6.4.0, 6.3.3, or 5.19.12, which fixes the issue.

Denial of service Server

Transient DOS when processing a malformed NR RRC configuration message due to improper input validation.

Denial of service

IBM API Connect 10.0.8.0 through 10.0.8.12 and 12.1.0.0 through 12.1.1.2 could allow a remote authenticated attacker to cause a denial of service due to incorrect type conversion. A value is converted incorrectly between two different types, which could cause the service to return invalid responses or become unavailable.

Denial of service

Scriban and Scriban.Signed before 7.5.3 contain uncontrolled recursion flaws in which postfix member, indexer, and call chains bypass ExpressionDepthLimit, array comparison lacks depth and cycle checks, and object.eval bypasses RecursiveLimit. Attackers who can supply templates can trigger an uncatchable StackOverflowException that terminates the host process.

Denial of service

IBM Db2 Genius Hub 1.1.2, 1.1.3, 1.1.4, 1.1.5 could allow a remote authenticated attacker to cause a denial of service due to improper validation of user-influenced resource identifiers.

Denial of service Device

A vulnerability was detected in OpenBMB Internet of Agents up to 9d78e88e47160eb42ee1ee8538c05e1c2c47877a. This affects the function launch_goal of the file im_client/communication/communication_layer.py of the component Collaboration Layer. Performing a manipulation of the argument max_turns results in infinite loop. The attack may be initiated remotely. The exploit is now public and may be used. This product uses a rolling release model to deliver continuous updates. As a result, specific version information for affected or updated releases is not available. The project was informed of the problem early through an issue report but has not responded yet.

Denial of service

VRPN through 07.36 contains an out-of-bounds stack write vulnerability in vrpn_Endpoint::handle_sender_message() and handle_type_message() that allows unauthenticated remote peers to write outside a stack buffer via an unchecked length index. Attackers can connect, complete the version-cookie exchange, and send a SENDER_DESCRIPTION or TYPE_DESCRIPTION message with an out-of-range or negative index to crash the process.

Denial of service Device

Converting crafted BIG-HKSCS input to UCS-4 or the internal wide character encoding, for example with iconv, in the GNU C Library version 2.18 through 2.31 may result in the converter making no progress, causing the calling application to hang.

Denial of service Library

Zulip is an open-source team collaboration tool. In Zulip Server versions through 12.1, the authenticated POST /messages/render endpoint renders the content parameter without enforcing the normal message length limit used by message send and edit operations. An authenticated user can submit Markdown up to the server body-size limit, causing disproportionate backend CPU consumption, and repeated or concurrent requests can degrade Markdown rendering performance or backend availability for other users. This issue is fixed in version 12.2.

Denial of service Web app

Zebra from 2.3.0 before 7.0.0 contains a denial of service vulnerability that allows unauthenticated peers to evade misbehavior scoring by sending transactions or blocks with invalid transparent scripts. Attackers can flood mempool with script-failing transactions or serve forged v5 block bodies with altered scriptSig bytes to exhaust CPU and repeatedly stall block sync.

Denial of service