CVE-2026-107820
What it is
x64dbg-MCP Server is a native Model Context Protocol (MCP) plugin for x64dbg that exposes the debugger's full functionality over HTTP. Prior to 1.2, src/core/mcp_server.zig parses an unbounded Content-Length value in parseContentLength() and uses it in unchecked usize addition in wsRecv() before token authentication. The server listens on 0.0.0.0 by default in affected versions. An unauthenticated network client can supply a near-maximum Content-Length value to trigger a runtime integer-overflow panic in Debug and ReleaseSafe builds, terminating the entire x64dbg process and its live debugging session. The overflowed value is used only in a comparison, so the impact is limited to denial of service rather than memory corruption or code execution. This issue is fixed in version 1.2.
At a glance
- Exploitability
- Can be exploited over the network without logging in. Limited direct impact.
- Exploit odds
- 0.4% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.4% in the next 30 days (EPSS).
- Severity: 5.3 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.4% · EPSS, next 30 days
- Weakness
- CWE-190 · Integer overflow
- Record status
- Awaiting Analysis
Attack profile CVSS 3.1 · 5.3
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- Low
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-107820.md and follow it. Check whether this project is affected by CVE-2026-107820. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://github.com/duty1g/x64dbg-mcp-server/commit/0dd4204d37c81d8b605133dc48c14886eeac1562
- https://github.com/duty1g/x64dbg-mcp-server/releases/tag/v1.2
- https://github.com/duty1g/x64dbg-mcp-server/security/advisories/GHSA-4478-h5jv-647m
- https://github.com/duty1g/x64dbg-mcp-server/security/advisories/GHSA-jgj3-97w2-9v9r
References
- https://github.com/duty1g/x64dbg-mcp-server/commit/0dd4204d37c81d8b605133dc48c14886eeac1562
- https://github.com/duty1g/x64dbg-mcp-server/releases/tag/v1.2
- https://github.com/duty1g/x64dbg-mcp-server/security/advisories/GHSA-4478-h5jv-647m
- https://github.com/duty1g/x64dbg-mcp-server/security/advisories/GHSA-jgj3-97w2-9v9r