CVE-2025-59956
Severity CVSS v4.0:
Pending analysis
Type:
Unavailable / Other
Publication date:
30/09/2025
Last modified:
08/10/2025
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
Base Score 3.x
6.50
Severity 3.x
MEDIUM
Vulnerable products and versions
| CPE | From | Up to |
|---|---|---|
| cpe:2.3:a:coder:agentapi:*:*:*:*:*:*:*:* | 0.4.0 (excluding) |
To consult the complete list of CPE names with products and versions, see this page
References to Advisories, Solutions, and Tools
- https://github.blog/security/application-security/localhost-dangers-cors-and-dns-rebinding
- https://github.com/coder/agentapi/commit/5c425c62447b8a9eac19e9fc5a2eae7f0803f149
- https://github.com/coder/agentapi/pull/49
- https://github.com/coder/agentapi/releases/tag/v0.4.0
- https://github.com/coder/agentapi/security/advisories/GHSA-w64r-2g3w-w8w4
- https://mcpsec.dev/advisories/2025-09-19-coder-chat-exfiltration
- https://mcpsec.dev/advisories/2025-09-19-coder-chat-exfiltration/



