CVE-2026-32946

Harden-Runner is a CI/CD security agent that works like an EDR for GitHub Actions runners. In versions 2.15.1 and below, the Harden-Runner that allows bypass of the egress-policy: block network restriction using DNS queries over TCP. Egress policies are enforced on GitHub runners by filtering outbound connections at the network layer. When egress-policy: block is enabled with a restrictive allowed-endpoints list (e.g., only github.com:443), all non-compliant traffic should be denied. However, DNS queries over TCP, commonly used for large responses or fallback from UDP, are not adequately restricted. Tools like dig can explicitly initiate TCP-based DNS queries (+tcp flag) without being blocked. This vulnerability requires the attacker to already have code execution capabilities within the GitHub Actions workflow. The issue has been fixed in version 2.16.0.
Configurations

Configuration 1 (hide)

cpe:2.3:a:stepsecurity:harden-runner:*:*:*:*:community:*:*:*

History

24 Mar 2026, 13:12

Type Values Removed Values Added
First Time Stepsecurity harden-runner
Stepsecurity
References () https://github.com/step-security/harden-runner/releases/tag/v2.16.0 - () https://github.com/step-security/harden-runner/releases/tag/v2.16.0 - Product, Release Notes
References () https://github.com/step-security/harden-runner/security/advisories/GHSA-g699-3x6g-wm3g - () https://github.com/step-security/harden-runner/security/advisories/GHSA-g699-3x6g-wm3g - Vendor Advisory
CPE cpe:2.3:a:stepsecurity:harden-runner:*:*:*:*:community:*:*:*
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 2.7
Summary
  • (es) Harden-Runner es un agente de seguridad de CI/CD que funciona como un EDR para los runners de GitHub Actions. En las versiones 2.15.1 y anteriores, el Harden-Runner permite eludir la restricción de red 'egress-policy: block' utilizando consultas DNS sobre TCP. Las políticas de egreso se aplican en los runners de GitHub filtrando las conexiones salientes en la capa de red. Cuando 'egress-policy: block' está habilitado con una lista restrictiva de puntos finales permitidos (por ejemplo, solo github.com:443), todo el tráfico no conforme debería ser denegado. Sin embargo, las consultas DNS sobre TCP, comúnmente utilizadas para respuestas grandes o como alternativa a UDP, no están restringidas adecuadamente. Herramientas como dig pueden iniciar explícitamente consultas DNS basadas en TCP (bandera +tcp) sin ser bloqueadas. Esta vulnerabilidad requiere que el atacante ya tenga capacidades de ejecución de código dentro del flujo de trabajo de GitHub Actions. El problema ha sido solucionado en la versión 2.16.0.

20 Mar 2026, 04:16

Type Values Removed Values Added
New CVE

Information

Published : 2026-03-20 04:16

Updated : 2026-03-24 13:12


NVD link : CVE-2026-32946

Mitre link : CVE-2026-32946

CVE.ORG link : CVE-2026-32946


JSON object : View

Products Affected

stepsecurity

  • harden-runner
CWE
CWE-693

Protection Mechanism Failure

CWE-863

Incorrect Authorization