{"schema_version":"1.7.3","id":"GHSA-w64r-2g3w-w8w4","published":"2025-09-29T20:40:26Z","modified":"2025-10-23T20:33:23Z","aliases":["CVE-2025-59956","GO-2025-3991"],"summary":"Coder AgentAPI exposed user chat history via a DNS rebinding attack","details":"### Summary\nAgentAPI prior to version [0.4.0](https://github.com/coder/agentapi/releases/tag/v0.4.0) was susceptible to a client-side DNS rebinding attack when hosted over plain HTTP on localhost.\n\n### Impact\nAn attacker could have gained access to the `/messages` endpoint served by the Agent API. This allowed for the unauthorized exfiltration of sensitive user data, specifically local message history, which could've included secret keys, file system contents, and intellectual property the user was working on locally.\n\n### Remediation\nWe've [implemented](https://github.com/coder/agentapi/pull/49) an `Origin` and `Host` header validating middleware and set a secure by default configuration.\n\nPlease upgrade to version [0.4.0](https://github.com/coder/agentapi/releases/tag/v0.4.0) or later.\n\n### Credits\nWe'd like to thank [Evan Harris](https://github.com/eharris128) from [mcpsec.dev](https://mcpsec.dev/) for reporting this issue and following the coordinated disclosure [policy](https://coder.com/security/policy).","affected":[{"package":{"name":"github.com/coder/agentapi","ecosystem":"Go","purl":"pkg:golang/github.com/coder/agentapi"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"0.4.0"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/09/GHSA-w64r-2g3w-w8w4/GHSA-w64r-2g3w-w8w4.json"}}],"references":[{"type":"WEB","url":"https://github.com/coder/agentapi/security/advisories/GHSA-w64r-2g3w-w8w4"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-59956"},{"type":"WEB","url":"https://github.com/coder/agentapi/pull/49"},{"type":"WEB","url":"https://github.com/coder/agentapi/commit/5c425c62447b8a9eac19e9fc5a2eae7f0803f149"},{"type":"WEB","url":"https://github.blog/security/application-security/localhost-dangers-cors-and-dns-rebinding"},{"type":"PACKAGE","url":"https://github.com/coder/agentapi"},{"type":"WEB","url":"https://github.com/coder/agentapi/releases/tag/v0.4.0"},{"type":"WEB","url":"https://mcpsec.dev/advisories/2025-09-19-coder-chat-exfiltration"},{"type":"WEB","url":"https://pkg.go.dev/vuln/GO-2025-3991"}],"database_specific":{"cwe_ids":["CWE-290","CWE-350"],"github_reviewed":true,"github_reviewed_at":"2025-09-29T20:40:26Z","nvd_published_at":"2025-09-30T11:37:41Z","severity":"MODERATE"},"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N"}]}