API Vulnerability in HarnessRouter Affects Session Management
CVE-2026-125330

7.5HIGH

Key Information:

Vendor

Harnessrouter

Status
Harnessrouter
Vendor
CVE Published:
10 November 2026

What is CVE-2026-125330?

HarnessRouter, a self-hosted API for agent harnesses, has a vulnerability affecting versions 0.4.2 to 0.31.6. The flaw allows routes accepting session or response IDs to validate only the caller's organization without enforcing the workspace scope for non-default workspace API keys. A key holder can exploit this to access and manipulate sessions, conversation turns, files, and traces across different workspaces. While the vulnerability does not cross organizational boundaries, it poses significant risks to data confidentiality and integrity within an organization. The issue was addressed in version 0.31.7.

Affected Version(s)

harnessrouter >= 0.4.2, < 0.31.7

References

https://github.com/HarnessRouter/harnessrouter/security/a...
x_refsource_CONFIRM
https://github.com/HarnessRouter/harnessrouter/pull/417
x_refsource_MISC
https://github.com/HarnessRouter/harnessrouter/commit/249...
x_refsource_MISC

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
High
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.