{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "1.8.6"
              },
              {
                "introduced": "1.9.0"
              },
              {
                "fixed": "1.9.5"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "introduced": "338e6fb681369ff0537719095e22ce9dc602dbf0"
            },
            {
              "fixed": "5853918c4c6a7b12f8becf4bd11ff4362ebb9020"
            },
            {
              "fixed": "f7a4071c766ceea3915415e22134cbe3e581c420"
            },
            {
              "fixed": "0cdfdd5fa8f8514c82413025e1e0808866cf7c30"
            },
            {
              "fixed": "c1896f06df22cc0ca5658df3a8f6cd7ede4cd6ae"
            },
            {
              "fixed": "dec22ac01ad9620c96b7b9ac3ef636ea46d43bed"
            }
          ],
          "repo": "https://github.com/libgit2/libgit2",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-27m5-gxxh-x79j"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-770"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53585.json"
  },
  "details": "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, git_delta_apply in src/libgit2/delta.c trusts the attacker-controlled res_sz value parsed by hdr_sz from a delta object header and passes that amount to git__malloc before validating delta instructions. Malicious pack data supplied through git_clone, git_fetch, git_remote_fetch, git_indexer_append, or a local attacker-supplied repository can use a very small multi-level OFS_DELTA chain to retain extremely large allocations and exhaust memory. This issue is fixed in versions 1.8.6 and 1.9.5.",
  "id": "CVE-2026-53585",
  "modified": "2026-08-22T03:31:14.499263707Z",
  "published": "2026-08-20T18:37:44.115Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/libgit2/libgit2/releases/tag/v1.8.6"
    },
    {
      "type": "WEB",
      "url": "https://github.com/libgit2/libgit2/releases/tag/v1.9.5"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53585.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/libgit2/libgit2/security/advisories/GHSA-27m5-gxxh-x79j"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-53585"
    },
    {
      "type": "FIX",
      "url": "https://github.com/libgit2/libgit2/commit/0cdfdd5fa8f8514c82413025e1e0808866cf7c30"
    },
    {
      "type": "FIX",
      "url": "https://github.com/libgit2/libgit2/commit/c1896f06df22cc0ca5658df3a8f6cd7ede4cd6ae"
    },
    {
      "type": "FIX",
      "url": "https://github.com/libgit2/libgit2/commit/dec22ac01ad9620c96b7b9ac3ef636ea46d43bed"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "libgit2: Unbounded Memory Allocation via Delta Object Result-Size Header"
}