Auth bypass in Harnessrouter

CVE-2026-125330

HarnessRouter is a self-hosted unified API for agent harnesses. From version 0.4.2 until 0.31.7, routes that accept a session ID or response ID validate only the caller's organization and do not enforce the workspace scope of a non-default workspace API key. A key holder who learns a non-guessable identifier from another workspace in the same organization can read sessions, conversation turns, files, traces, and responses, overwrite files, cancel or delete sessions, and publish share links. The issue does not cross organization boundaries, and console users, organization keys, and Default Workspace keys intentionally retain organization-wide access. This issue is fixed in version 0.31.7.

Vulnerability class: IDOR (Insecure Direct Object Reference)

Published .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-125330?
CVE-2026-125330 is a high-severity vulnerability in Harnessrouter, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 7.5/10. Published 2026-11-10.
How severe is CVE-2026-125330?
High severity. CVSS v3 base score is 7.5 out of 10.