GHSA-w64r-2g3w-w8w4 · Severity: medium · Ecosystem: go — Coder AgentAPI exposed user chat history via a DNS rebinding attack
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.
Conclusion & alert: CVE-2025-59956 is rated Exploit Available (50/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.06%). Core evidence: 2 public exploit reference(s) are indexed (Exploit-DB). Mandatory action: Public exploits are available—assess exposure, apply mitigations, and prioritize patching.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
| EDB-ID | Source | Kind | Published | Link |
|---|---|---|---|---|
| — | nvd_ref | exploit_tag | Exploit-DB ↗ | |
| — | nvd_ref | exploit_tag | Exploit-DB ↗ |
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-03-09 | 0.05% | 0.06% | +0.02% |
| 2 | 2026-02-25 | 0.05% | 0.05% | -0.00% |
| 3 | 2025-11-21 | — | 0.05% | — |
Full EPSS history (6 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 6.5 | 3.1 | MEDIUM |
|
2.8 | 3.6 | [email protected] |
GHSA-w64r-2g3w-w8w4 · Severity: medium · Ecosystem: go — Coder AgentAPI exposed user chat history via a DNS rebinding attack
| URL | Tags |
|---|---|
| https://github.blog/security/application-security/localhost-dangers-cors-and-dns-rebinding | Technical Description |
| https://github.com/coder/agentapi/commit/5c425c62447b8a9eac19e9fc5a2eae7f0803f149 | Patch |
| https://github.com/coder/agentapi/pull/49 | Issue Tracking Patch |
| https://github.com/coder/agentapi/releases/tag/v0.4.0 | Release Notes |
| https://github.com/coder/agentapi/security/advisories/GHSA-w64r-2g3w-w8w4 | Patch Vendor Advisory |
| https://mcpsec.dev/advisories/2025-09-19-coder-chat-exfiltration | Exploit Third Party Advisory |
| https://mcpsec.dev/advisories/2025-09-19-coder-chat-exfiltration/ | Exploit Third Party Advisory |