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CVE

CWE

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CVE-2025-59956

Published: Sep 29, 2025

Modified: Sep 30, 2025

PUBLISHED

CVSS v3.1

6.5

MEDIUM

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.

Vendor	Product	Versions
coder	agentapi	affected `< 0.4.0`

Weaknesses (CWE)

CVSS v3.1 Details

CVSS v3.1 Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

None

References

https://github.com/coder/agentapi/security/advisories/GHSA-w64r-2g3w-w8w4

x_refsource_CONFIRM

https://github.com/coder/agentapi/pull/49

x_refsource_MISC

https://github.com/coder/agentapi/commit/5c425c62447b8a9eac19e9fc5a2eae7f0803f149

x_refsource_MISC

https://github.blog/security/application-security/localhost-dangers-cors-and-dns-rebinding

x_refsource_MISC

https://github.com/coder/agentapi/releases/tag/v0.4.0

x_refsource_MISC

https://mcpsec.dev/advisories/2025-09-19-coder-chat-exfiltration

x_refsource_MISC

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