CVE-2026-125331 HarnessRouter is a self-hosted unified API for running agent harnesses with sessions, streaming, files, cancellation, and failure handling.
- Exploited in the wild
- Not known
- Fix
- None listed
What is CVE-2026-125331?
CVE-2026-125331 is a critical vulnerability in harnessrouter, published on 10 Nov 2026.
Official description
HarnessRouter is a self-hosted unified API for running agent harnesses with sessions, streaming, files, cancellation, and failure handling. Prior to 0.31.8, a console that is not in self-hosted mode attaches the server's internal key to requests carrying an Authorization header before validating the bearer, while the service-only PUT and GET /v1/orgs/{org}/connections/{name}, PUT /v1/orgs/{org}/policy/{backend}, and /internal/* routes trust that key and take the organization from the URL. In a multi-organization deployment, a remote caller can use a made-up bearer to rewrite another organization's provider connection to an attacker-controlled endpoint, causing later prompts to be disclosed and attacker-controlled responses to influence tasks. This issue is fixed in version 0.31.8.
Which versions are affected by CVE-2026-125331?
How do I fix CVE-2026-125331?
No fix has been published for CVE-2026-125331 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-125331 being exploited?
There is no known exploitation of CVE-2026-125331 in the wild and no public exploit code.
Sources
Also known as GHSA-p6cq-54cg-8mpv.