VULNERABILITY INTELLIGENCE

CVE-2025-59956

CVSS score6.5 MEDIUM

EPSS probability0.43%

CISA KEVNot currently listed

Published2025-09-30

Last modified2026-06-17

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

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.

Weakness classification

security-advisories@github.com: CWE-350
nvd@nist.gov: CWE-290

Primary references

security-advisories@github.com — Technical Description
security-advisories@github.com — Patch
security-advisories@github.com — Issue Tracking, Patch
security-advisories@github.com — Release Notes
security-advisories@github.com — Patch, Vendor Advisory
security-advisories@github.com — Exploit, Third Party Advisory
134c704f-9b21-4f2e-91b3-4a467353bcc0 — Exploit, Third Party Advisory