CVE-2026-53586

{
  "id": "CVE-2026-53586",
  "sourceIdentifier": "[email protected]",
  "published": "2026-08-20T19:16:54.983",
  "lastModified": "2026-10-26T10:10:00.140",
  "vulnStatus": "Awaiting Analysis",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "libgit2 is a portable C implementation of the Git core methods provided as a linkable library with a solid API, allowing to build Git functionality into your application. Prior to 1.8.6 and 1.9.5, the built-in HTTP transport in src/libgit2/transports/http.c follows an offsite initial redirect, and handle_remote_auth and handle_auth pass transport->owner->url instead of transport->server.url to the credential callback when the redirected host returns 401 Unauthorized. A callback that scopes credentials to the original trusted URL can therefore return GIT_CREDENTIAL_USERPASS_PLAINTEXT credentials that libgit2 stores in transport->server.cred and sends as an Authorization header to the redirected host. An attacker who controls a trusted Git host or an open redirect on that host can disclose HTTP Basic credentials, personal access tokens, or equivalent credentials. This issue is fixed in versions 1.8.6 and 1.9.5."
    },
    {
      "lang": "es",
      "value": "libgit2 es una implementación portátil en C de los métodos centrales de Git proporcionada como una biblioteca enlazable con una API sólida, lo que permite integrar la funcionalidad de Git en su aplicación. Antes de las versiones 1.8.6 y 1.9.5, el transporte HTTP integrado en src/libgit2/transports/http.c sigue una redirección inicial externa, y handle_remote_auth y handle_auth pasan transport  ->  owner  ->  url en lugar de transport  ->  server.url a la función de devolución de llamada de credenciales cuando el host redirigido devuelve 401 Unauthorized. Una función de devolución de llamada que limita el alcance de las credenciales a la URL original de confianza puede, por lo tanto, devolver credenciales GIT_CREDENTIAL_USERPASS_PLAINTEXT que libgit2 almacena en transport  ->  server.cred y envía como una cabecera de autorización al host redirigido. Un atacante que controla un host Git de confianza o una redirección abierta en ese host puede divulgar credenciales HTTP Basic, tokens de acceso personal, o credenciales equivalentes. Este problema se corrige en las versiones 1.8.6 y 1.9.5."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "libgit2",
          "product": "libgit2",
          "versions": [
            {
              "version": "< 1.8.6",
              "status": "affected"
            },
            {
              "version": ">= 1.9.0, < 1.9.5",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N",
          "baseScore": 6.5,
          "baseSeverity": "MEDIUM",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "REQUIRED",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "availabilityImpact": "NONE"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 3.6
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-08-21T20:58:39.443105Z",
          "id": "CVE-2026-53586",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-200"
        },
        {
          "lang": "en",
          "value": "CWE-522"
        },
        {
          "lang": "en",
          "value": "CWE-601"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/libgit2/libgit2/commit/07de6a7e438f95ac9a6efd3222a82117e871ed27",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/libgit2/libgit2/commit/af2b29ad0a74d5bac9751376879ddaf848136d3b",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/libgit2/libgit2/commit/c1507abc44647b3acd832a33a5b1c8c9f5ba8821",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/libgit2/libgit2/releases/tag/v1.8.6",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/libgit2/libgit2/releases/tag/v1.9.5",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/libgit2/libgit2/security/advisories/GHSA-2889-x8f6-mc4x",
      "source": "[email protected]"
    }
  ]
}