---
id: "CVE-2026-125331"
page: "https://infrastack.ai/live/CVE-2026-125331"
kind: "vulnerability"
aliases: ["CVE-2026-125331"]
title: "HarnessRouter: forged bearer lets a remote caller hijack another org's AI connection"
severity: "critical"
cvss: 9.1
epss: null
exploited: false
status: "open"
category: "ai-tooling"
products: []
ecosystems: []
tags: ["agent-harness", "ai-tooling", "multi-tenant", "self-hosted"]
not_affected_if: ["self-hosted-mode", "single-organization-deployment", "version-0.31.8-or-later"]
published_at: "2026-11-10T19:21:10+00:00"
first_seen_at: "2026-11-10T19:25:14+00:00"
updated_at: "2026-11-10T19:25:48+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-125331", "first_seen_at": "2026-11-10T19:25:14+00:00"}]
exploit_sources: []
---

# HarnessRouter: forged bearer lets a remote caller hijack another org's AI connection

Link for people: https://infrastack.ai/live/CVE-2026-125331 (this .md is for agents)

HarnessRouter is a self-hosted API for running AI agent harnesses across sessions and streams. Before 0.31.8, a request with any made-up bearer token can rewrite another organization's model provider connection to an attacker-controlled endpoint, so prompts are leaked and attacker responses steer tasks.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the installed HarnessRouter version against `0.31.8`
- Confirm whether the deployment is multi-organization and not running in self-hosted mode
- Review whether the internet can reach the PUT `/v1/orgs/{org}/connections/{name}` and `/internal/*` routes

## Fix

- HarnessRouter: upgrade to `0.31.8`

## Timeline

- 2026-11-10T19:25:14+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-125331

## Documents

- [advisory] Vendor advisory: github.com https://github.com/HarnessRouter/harnessrouter/security/advisories/GHSA-p6cq-54cg-8mpv
- [fix] Patch: github.com https://github.com/HarnessRouter/harnessrouter/commit/28609ec65ed671112d7e5418926bbd3cb3b25c00
- [fix] Release notes: github.com https://github.com/HarnessRouter/harnessrouter/releases/tag/v0.31.8

## From the sources

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.

---

_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_