CVE-2026-32947
MEDIUM
CVSS 4.6
No EPSS data
Description
Harden-Runner is a CI/CD security agent that works like an EDR for GitHub Actions runners. In versions 2.15.1 and below, a DNS over HTTPS (DoH) vulnerability allows attackers to bypass egress-policy: block network restrictions by tunneling exfiltrated data through permitted HTTPS endpoints like dns.google. The attack works by encoding sensitive data (e.g., the runner's hostname) as subdomains in DoH queries, which appear as legitimate HTTPS traffic to Harden-Runner's domain-based filtering but are ultimately forwarded to an attacker-controlled domain. This effectively enables data exfiltration without directly connecting to any blocked destination. Exploitation requires the attacker to already have code execution within the GitHub Actions workflow. The issue was fixed in version 2.16.0.
CVSS details
EPSS
This CVE is not currently listed in the EPSS dataset.
Show JSON
{
"cve": {
"id": "CVE-2026-32947",
"cveTags": [],
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"source": "nvd@nist.gov",
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"version": "3.1",
"baseScore": 4.9,
"attackVector": "NETWORK",
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N",
"integrityImpact": "NONE",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "NONE",
"privilegesRequired": "HIGH",
"confidentialityImpact": "HIGH"
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"exploitabilityScore": 1.2
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"version": "4.0",
"Recovery": "NOT_DEFINED",
"baseScore": 4.6,
"Automatable": "NOT_DEFINED",
"attackVector": "NETWORK",
"baseSeverity": "MEDIUM",
"valueDensity": "NOT_DEFINED",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"exploitMaturity": "NOT_DEFINED",
"providerUrgency": "NOT_DEFINED",
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"attackRequirements": "PRESENT",
"privilegesRequired": "HIGH",
"subIntegrityImpact": "NONE",
"vulnIntegrityImpact": "NONE",
"integrityRequirement": "NOT_DEFINED",
"modifiedAttackVector": "NOT_DEFINED",
"subAvailabilityImpact": "NONE",
"vulnAvailabilityImpact": "NONE",
"availabilityRequirement": "NOT_DEFINED",
"modifiedUserInteraction": "NOT_DEFINED",
"modifiedAttackComplexity": "NOT_DEFINED",
"subConfidentialityImpact": "HIGH",
"vulnConfidentialityImpact": "NONE",
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"modifiedAttackRequirements": "NOT_DEFINED",
"modifiedPrivilegesRequired": "NOT_DEFINED",
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"modifiedVulnIntegrityImpact": "NOT_DEFINED",
"vulnerabilityResponseEffort": "NOT_DEFINED",
"modifiedSubAvailabilityImpact": "NOT_DEFINED",
"modifiedVulnAvailabilityImpact": "NOT_DEFINED",
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"published": "2026-03-20T05:16:13.923",
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"tags": [
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"value": "CWE-693"
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"value": "CWE-863"
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"value": "Harden-Runner is a CI/CD security agent that works like an EDR for GitHub Actions runners. In versions 2.15.1 and below, a DNS over HTTPS (DoH) vulnerability allows attackers to bypass egress-policy: block network restrictions by tunneling exfiltrated data through permitted HTTPS endpoints like dns.google. The attack works by encoding sensitive data (e.g., the runner's hostname) as subdomains in DoH queries, which appear as legitimate HTTPS traffic to Harden-Runner's domain-based filtering but are ultimately forwarded to an attacker-controlled domain. This effectively enables data exfiltration without directly connecting to any blocked destination. Exploitation requires the attacker to already have code execution within the GitHub Actions workflow. The issue was fixed in version 2.16.0."
},
{
"lang": "es",
"value": "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 e inferiores, una vulnerabilidad de DNS sobre HTTPS (DoH) permite a los atacantes eludir las restricciones de red de 'egress-policy: block' al tunelizar datos exfiltrados a trav\u00e9s de puntos finales HTTPS permitidos como dns.google. El ataque funciona codificando datos sensibles (por ejemplo, el nombre de host del runner) como subdominios en consultas DoH, que aparecen como tr\u00e1fico HTTPS leg\u00edtimo para el filtrado basado en dominio de Harden-Runner pero que finalmente se reenv\u00edan a un dominio controlado por el atacante. Esto permite eficazmente la exfiltraci\u00f3n de datos sin conectarse directamente a ning\u00fan destino bloqueado. La explotaci\u00f3n requiere que el atacante ya tenga ejecuci\u00f3n de c\u00f3digo dentro del flujo de trabajo de GitHub Actions. El problema se solucion\u00f3 en la versi\u00f3n 2.16.0."
}
],
"lastModified": "2026-03-24T12:33:33.540",
"configurations": [
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