EUVD-2026-42809
GHSA-w2xj-h2fq-hcfv
Severity by source
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Network-accessible endpoint requiring low-privilege auth; no scope change; all impacts limited to Low given constrained authorization bypass.
Primary rating from Vendor (vuldb).
CVSS VectorVendor: vuldb
Lifecycle Timeline
1DescriptionCVE.org
A security flaw has been discovered in zhayujie CowAgent up to 2.1.0. The impacted element is an unknown function of the file channel/channel.py of the component Message Endpoint. The manipulation results in missing authorization. The attack may be launched remotely. The exploit has been released to the public and may be used for attacks. The project was informed of the problem early through an issue report but has not responded yet.
AnalysisAI
Missing authorization in zhayujie CowAgent up to version 2.1.0 allows remote attackers with low-privilege accounts to bypass access controls at the Message Endpoint defined in channel/channel.py, potentially enabling unauthorized access to or manipulation of messaging data. The CVSS 4.0 vector confirms network-accessible exploitation requiring only low privileges, with low-level confidentiality, integrity, and availability impacts on the vulnerable system. A public proof-of-concept exploit has been released per VulDB, and the project maintainer has not yet responded to the coordinated disclosure filed via GitHub issue #2874.
Technical ContextAI
CowAgent (github.com/zhayujie/CowAgent) is an open-source AI agent/chatbot framework. The vulnerability resides in channel/channel.py at the Message Endpoint handler, classified under CWE-862 (Missing Authorization). CWE-862 describes code paths that perform sensitive operations without verifying that the caller holds sufficient authorization - distinct from authentication failures (CWE-306) in that a user may be authenticated but the system fails to verify they are permitted to perform the requested action. Affected versions are CowAgent 2.0 and 2.1.0 per EUVD-2026-42809. No CPE string was provided by NVD, so the affected product scope is derived from EUVD and the VulDB report.
RemediationAI
No vendor-released patch has been identified at time of analysis; the project maintainer has not responded to the disclosure filed in GitHub issue https://github.com/zhayujie/CowAgent/issues/2874. As a primary compensating control, restrict access to the CowAgent Message Endpoint so that only explicitly trusted and authorized users hold accounts - avoid exposing the instance to any untrusted authenticated users, as the authorization gap is at the per-action level rather than the login level. Network-level controls such as placing CowAgent behind a VPN or internal-only network boundary reduce the AV:N attack surface without requiring code changes, though this does not eliminate risk from internal users. Monitoring channel/channel.py request logs for anomalous or out-of-scope message operations can provide detection coverage. Organizations dependent on CowAgent should track the upstream repository and issue #2874 for patch availability, and plan to upgrade immediately upon release of a fixed version.
Same weakness CWE-862 – Missing Authorization
View allSame technique Authentication Bypass
View allShare
External POC / Exploit Code
Leaving vuln.today