Security advisory

{
  "id": "fc94eb6dee503f68ff1c99305c880117dfadba2fca3176f05de4b875863f870d",
  "url": "https://osv.dev/vulnerability/CVE-2020-36430",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2020-36430",
    "summary": "libass 0.15.x before 0.15.1 has a heap-based buffer overflow in decode_chars (called from decode_font and process_text) because the wrong integer data type is used for subtraction.",
    "evidence": "osv:CVE-2020-36430",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2020-36430",
      "aliases": [
        "CVE-2020-36430"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/libass/libass",
              "type": "GIT",
              "events": [
                {
                  "introduced": "d149636f502f5774ae1a8fb4c554b122674393b2"
                },
                {
                  "fixed": "5447214643eacef71776350e779adf4b6c07bb3b"
                },
                {
                  "fixed": "017137471d0043e0321e377ed8da48e45a3ec632"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:libass_project:libass:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0.15.0"
                      },
                      {
                        "fixed": "0.15.1"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "017137471d0043e0321e377ed8da48e45a3ec632"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "0.15.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-36430.json",
            "vanir_signatures": [
              {
                "id": "CVE-2020-36430-1e115502",
                "digest": {
                  "length": 1124,
                  "function_hash": "110991188393091881186985668039830991525"
                },
                "source": "https://github.com/libass/libass/commit/017137471d0043e0321e377ed8da48e45a3ec632",
                "target": {
                  "file": "libass/ass.c",
                  "function": "decode_font"
                },
                "deprecated": false,
                "signature_type": "Function",
                "signature_version": "v1"
              },
              {
                "id": "CVE-2020-36430-dd9ed4a7",
                "digest": {
                  "threshold": 0.9,
                  "line_hashes": [
                    "237761427446648667051004743683370618705",
                    "203614521959843642792803634604266039747",
                    "167057952582482068803313308181837134398",
                    "185673660414575620126904484215688046936",
                    "78573754609072835798149174981656735930",
                    "103499063678342063401077868684384475532",
                    "334814143342617232491248731862329862754",
                    "124461199810427598757175082018620638494"
                  ]
                },
                "source": "https://github.com/libass/libass/commit/017137471d0043e0321e377ed8da48e45a3ec632",
                "target": {
                  "file": "libass/ass.c"
                },
                "deprecated": false,
                "signature_type": "Line",
                "signature_version": "v1"
              }
            ],
            "vanir_signatures_modified": "2026-10-20T14:12:23Z"
          }
        }
      ],
      "modified": "2026-10-20T14:12:23.796043526Z",
      "provider": "osv",
      "references": [
        "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6JUXFQUJ32GWG5E46A63DFDCYJAF3VU6/",
        "https://github.com/google/oss-fuzz-vulns/blob/main/vulns/libass/OSV-2020-2099.yaml",
        "https://security.gentoo.org/glsa/202208-13",
        "https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=26674",
        "https://github.com/libass/libass/commit/017137471d0043e0321e377ed8da48e45a3ec632"
      ],
      "provider_metadata": {
        "unresolved_ranges": [
          {
            "cpes": [
              "cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*"
            ],
            "vendor_product": "fedoraproject:fedora",
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "34"
                  },
                  {
                    "last_affected": "34"
                  }
                ],
                "source": "CPE_STRING"
              }
            ]
          }
        ]
      }
    },
    "related_cves": [
      {
        "value": "CVE-2020-36430",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 388716,
  "published_at": "2021-07-20T07:15:07.817+00:00"
}