U.S. flag   An official website of the United States government
Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Https

Secure .gov websites use HTTPS
A lock (Dot gov) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2025-59956 Detail

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.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

By selecting these links, you will be leaving NIST webspace. We have provided these links to other web sites because they may have information that would be of interest to you. No inferences should be drawn on account of other sites being referenced, or not, from this page. There may be other web sites that are more appropriate for your purpose. NIST does not necessarily endorse the views expressed, or concur with the facts presented on these sites. Further, NIST does not endorse any commercial products that may be mentioned on these sites. Please address comments about this page to [email protected].

URL Source(s) Tag(s)
https://github.blog/security/application-security/localhost-dangers-cors-and-dns-rebinding GitHub, Inc. Technical Description 
https://github.com/coder/agentapi/commit/5c425c62447b8a9eac19e9fc5a2eae7f0803f149 GitHub, Inc. Patch 
https://github.com/coder/agentapi/pull/49 GitHub, Inc. Issue Tracking  Patch 
https://github.com/coder/agentapi/releases/tag/v0.4.0 GitHub, Inc. Release Notes 
https://github.com/coder/agentapi/security/advisories/GHSA-w64r-2g3w-w8w4 GitHub, Inc. Patch  Vendor Advisory 
https://mcpsec.dev/advisories/2025-09-19-coder-chat-exfiltration GitHub, Inc. Exploit  Third Party Advisory 
https://mcpsec.dev/advisories/2025-09-19-coder-chat-exfiltration/ CISA-ADP Exploit  Third Party Advisory 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-290 Authentication Bypass by Spoofing cwe source acceptance level NIST  
CWE-350 Reliance on Reverse DNS Resolution for a Security-Critical Action GitHub, Inc.  

Known Affected Software Configurations Switch to CPE 2.2

CPEs loading, please wait.

Denotes Vulnerable Software
Are we missing a CPE here? Please let us know.

Change History

3 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2025-59956
NVD Published Date:
09/30/2025
NVD Last Modified:
10/08/2025
Source:
GitHub, Inc.