HarnessRouter: A workspace's API key could read and change sessions, files and responses of other workspaces in the same organization
- Exploited
- No known exploitation
- Fix
- Fixed in 0.31.7
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 0.31.7.
- Last modified
- Whether it needs action now or is a reference record, by fixed rules, with why. Last checked is when cve.now last re-read it.What do these mean? →
- Reference
- Last checked
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 11/100 · provisional
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
HarnessRouter, a self-hosted unified API for agent harnesses, has a flaw where a non-default workspace API key can access other workspaces' sessions, files, and responses within the same organization. An attacker with such a key can reach this remotely over the network after logging in with a low-privilege account, provided they learn a non-guessable session or response ID from another workspace, and can then read or change that data, cancel or delete sessions, and publish share links.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
Read the original description
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.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure3/25Reachable over the network · Unknown: No advisory context yet
- Reach?/20Unknown. No tracked technology or package matched
- Severity7.5/10CVSS 7.5
- No patch0/5No signal
What would change the score
- Would score about 66 if added to CISA KEV
- Would score about 61 if CISA's SSVC rates exploitation active
- Would score about 30 if advisories confirm default setups are exposed
What to do
Upgrade to a fixed version: 0.31.7.
Check your systems with an agent
Paste this into a coding or ops agent. It checks your systems read-only and reports a table per asset.
Check whether my systems are affected by CVE-2026-125330 (HarnessRouter: A workspace's API key could read and change sessions, files and responses of other workspaces in the same organization), using the cve.now data below. Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only. What cve.now has for CVE-2026-125330 (entry last updated 2026-11-10): Affected: - HarnessRouter harnessrouter: from 0.4.2, fixed in 0.31.7 Fixed versions: 0.31.7. Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory. CISA KEV: CVE-2026-125330 is not listed as of cve.now's last read. This KEV status is for CVE-2026-125330 only. If you also check another CVE, look up its own KEV status; never assume it from this one. How to check: - Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory. Verify against the linked advisories before concluding, and cite the date you read each one: - https://github.com/HarnessRouter/harnessrouter/security/advisories/GHSA-9pjr-97x3-c4wv - https://github.com/HarnessRouter/harnessrouter/pull/417 - https://github.com/HarnessRouter/harnessrouter/commit/249c6cc9ab51a24a78f4e9809d356718f2ef74b1 - https://github.com/HarnessRouter/harnessrouter/releases/tag/v0.31.7 Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing. Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action. Entry: https://cve.now/CVE-2026-125330 For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example get_vulnerability with id CVE-2026-125330.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- HarnessRouter harnessrouter
From 0.4.2 · fixed in 0.31.7
Evidence 6
Vendor advisory · 1
Establishes: Affected and fixed versions.
- Advisory
CVE record · 2
Establishes: The identifier and description.
- Record
- Record
Other links · 3
- Repository
- Repository
- Repository
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-125330
Is CVE-2026-125330 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
Which versions are affected by CVE-2026-125330?
harnessrouter: from 0.4.2 before 0.31.7.Source: cve.now feed data
How do I fix CVE-2026-125330?
Upgrade to a fixed version: 0.31.7.Source: cve.now feed data