CVE-2026-107820 json
x64dbg-MCP Server vulnerable to pre-authentication denial of service through Content-Length integer overflow
published 2026-10-09 30 d ago modified 2026-10-16 23 d ago also EUVD-2026-95928
- cvss
- 5.3
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 35%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 26 d ago
Exploit prediction
0.41% chance of exploitation in the next 30 days, higher than 35% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |
Affected products
- duty1g x64dbg-mcp-server
Classification
- Weakness
-
- CWE-190 Integer Overflow or Wraparound
References
Sources
- CVE List CVE-2026-107820
- NVD CVE-2026-107820
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