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 /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.
EPSS: 0.004 (35.6th 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
- security-advisories@github.com (x_refsource_CONFIRM, Patch, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC, Issue Tracking)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Technical Description, x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
- security-advisories@github.com (Exploit, Third Party Advisory, x_refsource_MISC)
- 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Exploit, Third Party Advisory)
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 2025-09-30.
- 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.