CVE-2026-53583

{
  "id": "CVE-2026-53583",
  "sourceIdentifier": "[email protected]",
  "published": "2026-08-20T19:16:54.500",
  "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, verify_server_cert in src/libgit2/streams/openssl.c uses an inverted !!memcmp result in the GEN_IPADD branch when comparing an IP-literal host with a certificate IP SubjectAltName. OpenSSL builds reject matching IP addresses and accept mismatched IP addresses, allowing a network attacker with a CA-trusted certificate containing any IP SubjectAltName to intercept libgit2 connections to IP-literal HTTPS URLs. DNS SubjectAltName validation and non-OpenSSL TLS backends are not affected. 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, permitiendo integrar la funcionalidad de Git en su aplicación. Antes de 1.8.6 y 1.9.5, verify_server_cert en src/libgit2/streams/openssl.c usa un resultado !!memcmp invertido en la rama GEN_IPADD al comparar un host literal de IP con un SubjectAltName de IP de certificado. Las compilaciones de OpenSSL rechazan las direcciones IP coincidentes y aceptan las direcciones IP no coincidentes, permitiendo a un atacante de red con un certificado de confianza de CA que contenga cualquier SubjectAltName de IP interceptar conexiones de libgit2 a URLs HTTPS literales de IP. La validación de DNS SubjectAltName y los backends TLS que no son de OpenSSL no se ven afectados. Este problema está solucionado 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:N/S:U/C:L/I:L/A:N",
          "baseScore": 6.5,
          "baseSeverity": "MEDIUM",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "LOW",
          "integrityImpact": "LOW",
          "availabilityImpact": "NONE"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 2.5
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-08-20T19:03:44.491440Z",
          "id": "CVE-2026-53583",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-295"
        },
        {
          "lang": "en",
          "value": "CWE-297"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/libgit2/libgit2/commit/647dcb432980b84ede4cb5a008bbd1ccb4ead03d",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/libgit2/libgit2/commit/c2aa35409ee0e6515df64da49750f13a0a42c47f",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/libgit2/libgit2/commit/ef086bc3e4eedf62be38a910381aae24d49871ff",
      "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-h7gc-w2gg-p9xp",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/libgit2/libgit2/security/advisories/GHSA-h7gc-w2gg-p9xp",
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
    }
  ]
}