CVE-2025-59956 | BDVDB-2026-295986 Detail
coderagentapi
Description#
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 /messages endpoint served by the Agent API. This allows for the unauthorized exfiltration of sensitive user data, specifically local message history, which can include secret keys, file system contents, and intellectual property the user was working on locally. This issue is fixed in version 0.4.0.
Impact#
Per CVSS v3.1: confidentiality impact high, integrity impact none, availability impact none. Attack vector: network.
Weaknesses#
- CWE-350 Reliance on Reverse DNS Resolution for a Security-Critical Action
References#
- https://github.com/coder/agentapi/security/advisories/GHSA-w64r-2g3w-w8w4
- https://github.com/coder/agentapi/pull/49
- https://github.com/coder/agentapi/commit/5c425c62447b8a9eac19e9fc5a2eae7f0803f149
- https://github.blog/security/application-security/localhost-dangers-cors-and-dns-rebinding
- https://github.com/coder/agentapi/releases/tag/v0.4.0
- https://mcpsec.dev/advisories/2025-09-19-coder-chat-exfiltration
- https://mcpsec.dev/advisories/2025-09-19-coder-chat-exfiltration/
Exploit#
History#
- Version 1Record published in the CVE List.
- Version 2Most recent update recorded in the CVE List.