Denial of service CVEs.
Published CVEs classified as denial of service, ranked by exploit odds.
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CVE-2026-126623
Inefficient algorithmic complexity in the JSON reader of Progressive Robot hMailServer 6.3.6 and 6.3.7 allows a remote attacker to hold the server's mail delivery threads or its REST API's worker threads, making mail delivery, the REST API and the webmail unavailable. 6.3.6 fixed CVE-2026-107574, in which reading a JSON object searched the member names already read for each new name, by keeping the names in a hash set; the set uses the standard library's hash, which takes no secret, so member names chosen to fall in one bucket of it still cost time growing with the square of their number. Against the released reader, one such object of 16 MB took about 5 seconds to read in the Linux build, and one of under 6 MB about 23 seconds in the Windows build, where objects of the same sizes with other names took under a tenth of a second. A remote unauthenticated attacker reaches the reader by mailing such an object as a TLS-RPT report, up to 16 MB once decompressed, to a hosted domain's report mailbox, where an administrator has set one; it is read on a mail delivery thread (ten by default), and those threads deliver all mail, local and outbound, so a stream of such reports stops all delivery for as long as it continues. It is also reached without an account through the reply to a password-protected message, with the message's link alone, where the REST API is on (it is off by default) and a public base URL for such links is set; and by any account through the webmail's routes granted 16 MB, and by an application's API key through the send API. Each such request holds one of the REST API's four worker threads, in the process that also serves SMTP, IMAP and POP3.
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CVE-2026-126613
Allocation of resources without limits in the JSON reader of Progressive Robot hMailServer 6.3.2 through 6.3.7 allows a remote attacker to exhaust the server's memory and hold its threads, making mail delivery, the REST API and the webmail unavailable. The reader built a tree of values far larger than the text it read, copying each value into every level above it, and set no bound on the number of values, so a single JSON document of many small values, within the 16 MB the server reads, raised the service's memory by about 2 GB and held one thread for seconds to minutes. From 6.3.4 a remote unauthenticated attacker reaches the reader by mailing such a document as a TLS-RPT report, up to 16 MB once decompressed, to a hosted domain's report mailbox, where an administrator has set one; it is read on a mail delivery thread (ten by default), and those threads deliver all mail, local and outbound. From 6.3.4 it is also reached without an account through the reply to a password-protected message, with the message's link alone, where the REST API is on (it is off by default) and a public base URL for such links is set; and by any account, from 6.3.2 through the webmail's send and draft routes and from 6.3.4 through its other routes granted 16 MB and the send API; the webmail's send, draft and settings routes parsed the body again for each member read. The REST API serves every request on four worker threads, in the process that also serves SMTP, IMAP and POP3, so a few such documents at once make it unavailable and can exhaust the machine's memory and end the whole service. This is a separate defect from CVE-2026-107574, the reader's handling of duplicate member names, fixed in 6.3.6.
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CVE-2026-126565
Semantic MediaWiki 3.0.0 before 7.4.1 contains a denial of service vulnerability in the ElasticStore and SPARQLStore ConceptDescriptionInterpreter classes, which re-expand concepts without memoization or an expansion budget. Users with page-edit rights can build acyclic chains of Concept: pages that fan out, so queries via concept page views, Special:Ask, or api.php action=ask exhaust CPU and memory.
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CVE-2026-126562
Semantic MediaWiki 3.0.0 before 7.4.1 contains an uncontrolled recursion vulnerability in the ElasticStore ConceptDescriptionInterpreter that only detects directly self-referencing concepts. Users with page-edit rights can create mutually referencing concept pages, causing concept page views, Special:Ask, or api.php action=ask queries to exhaust PHP memory or stack.
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CVE-2026-126546
Viber for iOS through 29.4.0.24 fails to validate the logical screen width and height in received GIF headers, allowing attackers to crash the app. Attackers can send a crafted GIF with zero dimensions that triggers an uncaught NSInternalInconsistencyException, aborting the app with SIGABRT when opened.
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CVE-2026-97054
For HTTP/1 servers, when MaxBytesReader's limit is exceeded, "Connection: close" header is automatically set without synchronization, which might race with another header being set explicitly in the server handler. As a result, an HTTP/1 server that utilizes MaxBytesReader or MaxBytesHandler can crash due to runtime panic if its handler reads the request body concurrently with writing the response header.
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CVE-2026-68538
fulgur converts untrusted HTML/CSS into PDF, commonly on a server that processes input supplied by many tenants. From version 0.15.0 to before version 0.27.0, resolving the CSS counters(name, sep) function in generated content was bounded neither in the size of a single expansion nor in the aggregate work across an element tree. An attacker able to submit HTML/CSS to a fulgur-based conversion service can trigger CPU and memory exhaustion with a trivially small payload, denying service to the host and any co-tenants. This issue has been patched in version 0.27.0.
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CVE-2026-68539
fulgur converts untrusted HTML/CSS into PDF, commonly on a server that processes input supplied by many tenants. From version 0.4.4 to before version 0.29.0, the CSS string-set named-string values resolved from a document were accumulated per element with no memory budget, letting a small crafted document amplify into large retained memory (and the CPU to copy it) — results in a denial of service. This issue has been patched in version 0.29.0.
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CVE-2026-68540
fulgur converts untrusted HTML/CSS into PDF, commonly on a server that processes input supplied by many tenants. From version 0.6.0 to before version 0.33.0, quadratic style-list reprocessing during containing-block resolution for absolutely-positioned pseudo-elements cause denial of service. This issue has been patched in version 0.33.0.
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CVE-2026-126244
A allocation of resources without limits or throttling vulnerability in Fortinet FortiAuthenticator 8.0.0 through 8.0.3, FortiAuthenticator 6.6.0 through 6.6.10 may allow an unauthenticated attacker to exhaust system resources, potentially resulting in a denial of service (DoS).
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CVE-2026-126237
A loop with unreachable exit condition ('infinite loop') vulnerability in Fortinet FortiAuthenticator 8.0.0 through 8.0.3, FortiAuthenticator 6.6.0 through 6.6.10 may allow an attacker to cause a denial of service via crafted TCP requests.
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CVE-2026-126230
A use of externally-controlled format string vulnerability in Fortinet FortiAnalyzer 8.0.0 through 8.0.1, FortiAnalyzer 7.6.0 through 7.6.7, FortiAnalyzer 7.4.0 through 7.4.11, FortiAnalyzer 7.2.0 through 7.2.12, FortiAnalyzer Cloud 8.0.0 through 8.0.1, FortiAnalyzer Cloud 7.6.0 through 7.6.7, FortiAnalyzer Cloud 7.4.1 through 7.4.11, FortiAnalyzer Cloud 7.2.1 through 7.2.12, FortiManager 8.0.0 through 8.0.1, FortiManager 7.6.0 through 7.6.7, FortiManager 7.4.0 through 7.4.11, FortiManager 7.2.0 through 7.2.12, FortiManager Cloud 8.0.0 through 8.0.1, FortiManager Cloud 7.6.0 through 7.6.7, FortiManager Cloud 7.4.1 through 7.4.11, FortiManager Cloud 7.2.1 through 7.2.12 may allow an authenticated administrator to execute unauthorized code or commands or cause a denial of service via specially crafted requests.
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CVE-2026-126161
A uncontrolled resource consumption vulnerability in Fortinet FortiMail 8.0.0 through 8.0.1, FortiMail 7.6.0 through 7.6.6, FortiMail 7.4.0 through 7.4.6 may allow a remote unauthenticated attacker to cause a denial of service via repeated unauthenticated POST requests.
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CVE-2026-126784
Missing rate limiting, per-account submission quota and geographic validation in the publicar_aviso RPC function in Lagarto Chivato 0.4.1 and earlier on Web allows remote authenticated attackers to flood the moderation queue via unlimited submission of notices with arbitrary coordinates.
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CVE-2026-91150
A flaw was found in Cockpit. This vulnerability allows a remote attacker, without prior authentication, to send specially crafted fragmented WebSocket messages. These messages accumulate without a total-size limit, leading to unbounded memory exhaustion and a denial of service in the `cockpit-ws` service.
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CVE-2026-64861
Probo is a self-hostable governance, risk, and compliance (GRC) platform built for engineering and security teams. Prior to version 0.222.0, the GraphQL endpoint does not enforce restrictions on alias count, query depth, or query complexity. An attacker can send a single request containing thousands of aliased resolver calls, causing excessive server-side resource consumption and service degradation. This issue has been patched in version 0.222.0.
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CVE-2026-58505
geojson-vt is a JavaScript library for slicing GeoJSON data into vector tiles on the fly, primarily designed to enable rendering and interacting with large geospatial datasets on the browser side (without a server). Prior to version 6.1.1, @maplibre/geojson-vt contains an uncontrolled recursion vulnerability in its GeoJSON conversion logic. When a GeoJSONVT instance is constructed with a deeply nested GeometryCollection object, the mutually recursive functions featureToInternal and convertGeometryCollection in src/convert.ts exhaust the Node.js call stack, causing an unhandled RangeError: Maximum call stack size exceeded that terminates the process. Because the library is widely used in server-side tile services that accept GeoJSON over the network, a remote unauthenticated attacker can trigger a denial-of-service by sending a single crafted payload. No authentication is required, and no non-default library options are needed. This issue has been patched in version 6.1.1.
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CVE-2026-123865
An unauthenticated HTTP/2 client can permanently leak Node.js server memory and file descriptors. If a peer triggers a protocol error, for example an oversized frame header, while the session is already shutting down, nghttp2 tears the session down internally but Node.js never notices, leaving a dangling session: the socket stays in CLOSE_WAIT and all of Node.js's HTTP/2 state for that connection is held in memory indefinitely, with no further cost to the attacker. The attacker can start the shutdown remotely by sending GOAWAY(NO_ERROR), so it is reliable against default HTTP/2 servers. It is an incomplete-fix case of CVE-2026-48937: that fix detected nghttp2 internal terminations by watching for GOAWAY sent while not shutting down, but missed terminations that arrive while the session is already shutting down. This vulnerability affects Node.js 26.x, 24.x, and 22.x.
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CVE-2026-123868
An unauthenticated HTTP/2 client can exhaust Node.js server memory because inbound DATA queued on an undrained stream is charged to no session budget. Each inbound DATA frame creates one JavaScript Buffer view in the receiving stream's readable queue, but nothing charges that queue to current_session_memory_: the socket read buffer is accounted only during parsing and released immediately, so whatever stays queued is accounted to nothing. A peer that fills a stream's receive window with one-byte DATA frames pays about 10 wire bytes per frame while the server retains about 114 bytes per frame, so a single stream on one connection can retain hundreds of megabytes from tens of megabytes sent. maxSessionMemory neither bounds the growth nor refuses new streams, because Http2Session::CanAddStream gates admission on the same counter that never sees the queue. This vulnerability affects Node.js 26.x and 24.x.
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CVE-2026-123862
An uncatchable exception in the Node.js zlib streaming API lets a peer crash a process by disconnecting while data is being compressed. zlib.params() queues a flush and completes its work in that write's callback; if the stream is destroyed first, as pipeline() does when the peer goes away, Writable still invokes the callback with an error, but the callback ignores its arguments and asserts that the native handle still exists. The handle is gone, so an ERR_INTERNAL_ASSERTION is thrown from inside stream internals and bypasses the stream's error event, the params() callback, and the pipeline() callback, terminating the process. An application is affected only if it calls deflate.params() while streaming to a peer, which is uncommon. This vulnerability affects Node.js 26.x, 24.x, and 22.x.
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CVE-2026-123863
A reachable assertion in Node.js HTTP/2 session teardown lets any unauthenticated client abort the server, over both TLS and cleartext. A client can arrange for an Http2Stream that still holds nghttp2-allocated header buffers to outlive its session: the stream is removed from the session's stream set but never detached, so when ~Http2Session() runs the memory accounting is nonzero and the CHECK_EQ(current_nghttp2_memory_, 0) assertion fails, terminating the process. The trigger needs only a default http2 server whose handler responds before the request body has ended, which is typical. It is a variant of CVE-2024-27983 that the earlier fix did not cover, because that fix only detached streams still tracked in the session. This vulnerability affects Node.js 26.x (since 26.9.0) and 24.x (since 24.22.0).
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CVE-2026-61619
The OWASP core rule set (CRS) is a set of generic attack detection rules for use with compatible web application firewalls. Prior to versions 3.3.10, 4.25.1, and 4.28.0, regular-expression denial of service (ReDoS) affects a shared regex-assembly include used to build 12 Unix RCE detection rules in CRS v4, and the same ambiguous pattern was present in the manually-assembled regexes in 4 rules in CRS v3.3. With a single, unauthenticated, crafted request, the generated pattern drives PCRE2 past its backtracking limit. When PCRE2 exceeds that limit, the @rx operator returns an error rather than a match result, which results in detection bypass and CPU denial of service. This issue has been patched in versions 3.3.10, 4.25.1, and 4.28.0.
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CVE-2026-106156
In Progress® Telerik® UI for ASP.NET Core versions `2015.1.318` through `2026.3.811`, repeated server-side aggregation requests, with or without grouping, cause dynamic assemblies and load contexts to be retained, resulting in accumulating process memory consumption. An unauthenticated remote attacker can exploit this if the application exposes an aggregation endpoint that is reachable without authentication. Repeated requests can cause memory growth that may exhaust available resources and affect application availability. Disabling grouping in the client-side interface does not prevent direct requests containing these descriptors. The issue is fixed in version `2026.3.1015`.
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CVE-2026-119723
When parsing request variables such as query-string and form parameters, HHVM did not check that appending a nested array succeeded before descending into it. A remote, unauthenticated attacker could send a GET or POST request which would crash the HHVM server process before any application code runs, leading to denial of service. This issue affected HHVM prior to 23c061f4e804a51badd5f85227e65185651253b5.
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CVE-2026-121737
When a remote, unauthenticated HTTP/1.1 client pipelined the start of a second request and then stopped reading, proxygen's coroutine-based HTTP session could free that pipelined stream while resetting the connection's streams on the resulting write timeout, then go on to use it. This can crash the server, leading to denial of service, and may allow memory corruption with further impact. This issue affects proxygen versions prior to v2026.11.09.00.
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CVE-2026-119233
proxygen's HTTP/3 codec buffered an incomplete non-DATA frame, such as a control-stream frame, a frame of an unknown or reserved type, or a HEADERS frame, until its entire declared length had arrived, without limiting that length, and re-scanned all buffered data each time more bytes arrived. A remote, unauthenticated HTTP/3 peer could declare a very large frame and deliver it slowly, causing unbounded memory growth and CPU usage that grows quadratically with the number of fragments, leading to denial of service. This issue affects proxygen versions prior to v2026.11.09.00.
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CVE-2026-119234
mvfst did not adequately merge or compact out-of-order STREAM frame data, and a small received fragment could keep a much larger receive buffer alive. QUIC flow control limits the number of buffered stream bytes, but not this per-fragment memory and bookkeeping. A remote, unauthenticated QUIC peer could send many small, non-contiguous stream fragments to make an endpoint consume memory far in excess of its advertised receive window and spend increasing CPU time reassembling stream data, leading to denial of service. This issue affects mvfst versions prior to v2026.11.09.0.
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CVE-2026-119235
proxygen's QPACK decoder enforced its size limit on a string literal in an encoder-stream instruction only after the entire literal had been received. A remote, unauthenticated HTTP/3 peer could send an insert instruction on the QPACK encoder stream that declares an arbitrarily large literal and then keep sending data, causing the decoder to buffer it without bound for the lifetime of the connection and exhaust memory, leading to denial of service. The issue occurs regardless of the advertised QPACK dynamic table capacity, including when the dynamic table is disabled. This issue affects proxygen versions prior to v2026.11.09.00.
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CVE-2026-119236
An mvfst QUIC server retained CRYPTO frame data received at an encryption level (Initial or Handshake) that the TLS handshake had already moved past. Because the transport treated this data as delivered, it did not count against the CRYPTO stream buffer limit. A remote, unauthenticated client could complete a handshake, withhold its acknowledgment of the server's HANDSHAKE_DONE frame so that Handshake keys stay in use, and keep sending Handshake-level CRYPTO data at increasing offsets, causing unbounded memory growth on the server and leading to denial of service. This issue affects mvfst versions prior to v2026.11.09.00.
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CVE-2026-119237
In proxygen's HTTP/3 session, when a HEADERS block referenced QPACK dynamic table entries that had not yet been received, header decoding for that stream was paused, but the session continued to read the stream from the QUIC transport. The unread data bypassed the session's ingress buffer limit, returned flow-control credit to the peer, and was re-scanned in full on every read. With QPACK blocked streams enabled (the default), a remote, unauthenticated HTTP/3 peer could send a HEADERS block that references a dynamic table insert it never sends, followed by a continuous stream of data, causing memory growth until the request timed out and CPU usage that grows quadratically, leading to denial of service. This issue affects proxygen versions prior to v2026.11.09.00.
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CVE-2026-107509
A user with the Viewer role can make Grafana allocate an unbounded amount of memory, and crash it, with a single SQL Expression query that casts a value to a very large BINARY length (memory allocation with excessive size value).
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CVE-2026-126659
BlueprintUE Self-Hosted Edition 1.0.0 before 4.3.5 contains a resource exhaustion vulnerability that allows unauthenticated attackers to fill server storage by repeatedly creating anonymous blueprints. Attackers can send large requests to HomeController::doProcessCreateBlueprint() with a 'never' expiration, bypassing purges to fill the disk and deny service.
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CVE-2026-122096
Uncontrolled Resource Consumption vulnerability in the sketch deserialization of Apache DataSketches Java. Several deserializers trusted sizes and counts declared in the serialized input. A small crafted input could make an application allocate an excessive amount of memory, leading to an OutOfMemoryError. A crafted string passed to FrequentLongsSketch.getInstance(String) could also make deserialization, or a later update, loop indefinitely. Only applications that deserialize sketches from untrusted sources are affected. This issue affects Apache DataSketches Java: through 9.0.0. Users are recommended to upgrade to version 9.1.0, which fixes the issue.
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CVE-2026-124743
A flaw was found in BusyBox. When processing filesystem metadata, the volume identification component does not properly validate header values in HFS+ filesystems. An attacker able to attach a storage device or supply a specially crafted filesystem image can trigger an application crash, resulting in a Denial of Service (DoS) and preventing device resolution.
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CVE-2026-124742
A flaw was found in BusyBox. The volume identification component fails to properly validate cluster parameters when analyzing specially formatted FAT filesystems. An attacker able to present a crafted storage device or disk image can trigger a divide-by-zero condition when partition scanning utilities inspect the volume. This issue causes the probing utilities to crash unexpectedly, resulting in a Denial of Service (DoS) that can disrupt device discovery and system boot operations.
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CVE-2026-111792
Uncontrolled Recursion vulnerability in Apache XML Graphics Batik. This issue affects Apache XML Graphics Batik: through 1.19. Users are recommended to upgrade to version 1.20, which fixes the issue.
A list of CVEs whose flaw type is denial of service, sorted by how likely they are to be exploited (EPSS). Classification uses the CWE weakness id where present, and a small local model otherwise.