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CVE-2026-1999

Estado: ModificadaAlta (7.1)—

An incorrect authorization vulnerability was identified in GitHub Enterprise Server that allowed an attacker to merge their own pull request into a repository without having push access by exploiting an authorization bypass in the enable_auto_merge mutation for pull requests. This issue only affected repositories that allow forking as the attack relies on opening a pull request from an attacker-controlled fork into the target repository. Exploitation was only possible in specific scenarios.

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It required a clean pull request status and only applied to branches without branch protection rules enabled. This vulnerability affected GitHub Enterprise Server versions prior to 3.19.2, 3.18.5, and 3.17.11, and was fixed in versions 3.19.2, 3.18.5, and 3.17.11. This vulnerability was reported via the GitHub Bug Bounty program.

CVSS

Probabilidad de explotación (EPSS)

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

Vector CVSS con AV:N, PR:L, VI:H indica acceso remoto con privilegios mínimos que deriva en cambios de integridad. Authorization bypass en mutation de pull requests permite manipular código sin permisos, alterando repositorio (T1565.002) y efectivamente elevando privilegios de cuenta (T1078).

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Privileged Account ManagementApplication Developer GuidanceActive Directory ConfigurationVulnerability ScanningUser TrainingUser Account Management

Tecnologías afectadas (1)

Github — Enterprise Server

CWE

Referencias

JSON original (NVD)

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      "value": "An incorrect authorization vulnerability was identified in GitHub Enterprise Server that allowed an attacker to merge their own pull request into a repository without having push access by exploiting an authorization bypass in the enable_auto_merge mutation for pull requests. This issue only affected repositories that allow forking as the attack relies on opening a pull request from an attacker-controlled fork into the target repository. Exploitation was only possible in specific scenarios. It required a clean pull request status and only applied to branches without branch protection rules enabled. This vulnerability affected GitHub Enterprise Server versions prior to 3.19.2, 3.18.5, and 3.17.11, and was fixed in versions 3.19.2, 3.18.5, and 3.17.11. This vulnerability was reported via the GitHub Bug Bounty program."
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      "lang": "es",
      "value": "Una vulnerabilidad de autorización incorrecta fue identificada en GitHub Enterprise Server que permitía a un atacante fusionar su propia solicitud de extracción en un repositorio sin tener acceso de envío al explotar una omisión de autorización en la mutación enable_auto_merge para solicitudes de extracción. Este problema solo afectó a los repositorios que permiten la bifurcación, ya que el ataque se basa en abrir una solicitud de extracción desde una bifurcación controlada por el atacante en el repositorio objetivo. La explotación solo fue posible en escenarios específicos. Requería un estado de solicitud de extracción limpio y solo se aplicaba a ramas sin reglas de protección de rama habilitadas. Esta vulnerabilidad afectó a las versiones de GitHub Enterprise Server anteriores a 3.19.2, 3.18.5 y 3.17.11, y fue corregida en las versiones 3.19.2, 3.18.5 y 3.17.11. Esta vulnerabilidad fue reportada a través del programa GitHub Bug Bounty."
    }
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