CVSS 3.1
9.1 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:NCVE-2026-125331 HarnessRouter: Service-only routes that write an organization's provider connections could be reached through a multi-tenant console with a made-up bearer
Critical (9.1) in harnessrouter harnessrouter. EPSS 0.3% estimated probability of exploitation activity in the next 30 days.
On this page
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.
Severity
- EPSS
- 0.3% estimated probability of exploitation activity in the next 30 days; 23rd percentile. Scored 2026-11-13. A forecast for this CVE across the internet, not for your own systems.
- CISA's assessment (SSVC)
- Exploitation: none · Automatable: yes · Technical impact: total, assessed 2026-11-12. From CISA's Vulnrichment in the CVE List: whether it is exploited, whether exploiting it can be automated, and how much control it gives.
- OWASP Top 10
- A01:2025 Broken Access Control
- Published
- Modified
- Assigned by
- GitHub_M (CNA)
- NVD analysis
- Deferred: the NVD does not plan to analyze it
- Record from
- the NVD, synced
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Affected
Versions
From the CNA's record in the CVE List.
| Product | Affected |
|---|---|
| harnessrouter | < 0.31.8 |
Attack patterns (CAPEC)
- CAPEC-665 Exploitation of Thunderbolt Protection Flaws Likelihood: Low · Severity: Very High
The attack patterns MITRE's CAPEC relates to this record's weaknesses, as MITRE names them. Credits.
History
- The NVD deferred its analysis
Changes since this site first stored the record. The same for every record: /api/public/changes.
References
- https://github.com/HarnessRouter/harnessrouter/commit/28609ec65ed671112d7e5418926bbd3cb3b25c00
- https://github.com/HarnessRouter/harnessrouter/pull/418
- https://github.com/HarnessRouter/harnessrouter/releases/tag/v0.31.8
- https://github.com/HarnessRouter/harnessrouter/security/advisories/GHSA-p6cq-54cg-8mpv