CVE-2026-50141: Woodpecker CI agent impersonation via gRPC metadata injection

CVE-2026-50141 · Severity: high · CVSS 4 · Published 2026-06-18

A security vulnerability in Woodpecker CI, a popular continuous integration tool, allows an authenticated agent to impersonate other agents on the same server. By spoofing identification data, a malicious agent could potentially interfere with build processes or access data belonging to other tenants. This could lead to unauthorized modifications of software builds and disrupt development operations.

Technologies: go.woodpecker-ci.org/woodpecker (Go), go.woodpecker-ci.org/woodpecker/v2 (Go), Woodpecker CI Woodpecker. Vendors: Go, Woodpecker CI.

Quick answers

Is CVE-2026-50141 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-50141 being exploited in the wild.
How severe is CVE-2026-50141?
High severity, with a CVSS score of 4, published 18 June 2026.
Which products and versions are affected?
go.woodpecker-ci.org/woodpecker (Go) SEMVER:introduced=0; go.woodpecker-ci.org/woodpecker/v2 (Go) SEMVER:introduced=0; go.woodpecker-ci.org/woodpecker/v3 (Go) >= 3.0.0, < 3.14.1, SEMVER:introduced=3.0.0,fixed=3.14.1; Woodpecker CI Woodpecker >= 3.0.0, < 3.14.1.
Is there a fix for CVE-2026-50141?
Yes. go.woodpecker-ci.org/woodpecker/v3 (Go): upgrade to 3.14.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-50141 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-50141?
Check whether you run go.woodpecker-ci.org/woodpecker (Go), go.woodpecker-ci.org/woodpecker/v2 (Go), go.woodpecker-ci.org/woodpecker/v3 (Go) or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • go.woodpecker-ci.org/woodpecker/v3 (Go): upgrade to 3.14.1 or later
    go get go.woodpecker-ci.org/woodpecker/v3@v3.14.1

Technical details

A vulnerability exists in Woodpecker CI's gRPC communication layer (CWE-290, CWE-639) where the server fails to properly enforce the identity verified by a JWT token. While the server correctly validates the token, it subsequently discards the verified identity in favor of a client-supplied 'agent_id' value found in the gRPC metadata. An attacker with valid agent credentials can exploit this to impersonate any other agent on the same server. The issue is fixed in version 3.14.1. A workaround involves disabling user agent registration via the WOODPECKER_DISABLE_USER_AGENT_REGISTRATION environment variable.

Affected products

  • Woodpecker CI woodpecker-ci/woodpecker/v3 >= 3.0.0, < 3.14.1

Identifiers

  • CVE-2026-50141
  • GHSA-g7mm-9vx7-jm7h
  • GO-2026-5976

Timeline

  • 2026-06-03: disclosed: Vulnerability reported to Woodpecker CI
  • 2026-06-18: advisory: NVD publication date
  • 2026-07-14: patched: GitHub Advisory published and reviewed

References

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