CVE-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
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.
INFO
Published Date :
Nov. 10, 2026, 6:38 p.m.
Last Modified :
Nov. 10, 2026, 6:38 p.m.
Remotely Exploit :
Yes !
Source :
vulncheck-cvelist-v5
Affected Products
The following products are affected by CVE-2026-125331
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | CRITICAL | MITRE-CVE |
Solution
- Update HarnessRouter to version 0.31.8.
- Ensure self-hosted mode is configured if needed.
- Review organization URL handling.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-125331.
| URL | Resource |
|---|---|
| https://github.com/HarnessRouter/harnessrouter/security/advisories/GHSA-p6cq-54cg-8mpv | x_refsource_CONFIRM |
| https://github.com/HarnessRouter/harnessrouter/pull/418 | x_refsource_MISC |
| https://github.com/HarnessRouter/harnessrouter/commit/28609ec65ed671112d7e5418926bbd3cb3b25c00 | x_refsource_MISC |
| https://github.com/HarnessRouter/harnessrouter/releases/tag/v0.31.8 | x_refsource_MISC |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-125331 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-125331
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-125331 vulnerability anywhere in the article.