Vulnerability in Coder Agentapi
CVE-2025-59956
AgentAPI is an HTTP API for Claude Code, Goose, Aider, Gemini, Amp, and Codex. Versions 0.3.3 and below are susceptible to a client-side DNS rebinding attack when hosted over plain HTTP on localhost. An attacker can gain access to the /mes…
EPSS: 0.001 (22.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N.
Affected products
- Coder Agentapi — versions < 0.4.0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- https://github.com/coder/agentapi/security/advisories/GHSA-w64r-2g3w-w8w4 (x_refsource_CONFIRM)
- https://github.com/coder/agentapi/pull/49 (x_refsource_MISC)
- https://github.com/coder/agentapi/commit/5c425c62447b8a9eac19e9fc5a2eae7f0803f149 (x_refsource_MISC)
- https://github.blog/security/application-security/localhost-dangers-cors-and-dns-rebinding (x_refsource_MISC)
- https://github.com/coder/agentapi/releases/tag/v0.4.0 (x_refsource_MISC)
- https://mcpsec.dev/advisories/2025-09-19-coder-chat-exfiltration (x_refsource_MISC)
Frequently asked questions
- What is CVE-2025-59956?
- CVE-2025-59956 is a medium-severity vulnerability in Coder Agentapi, classified under CWE-350. CVSS score: 6.5/10. Published 2025-09-29.
- How severe is CVE-2025-59956?
- Medium severity. CVSS v3 base score is 6.5 out of 10.
- Is CVE-2025-59956 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.