FFmpeg - Out-of-Bounds Write in RASC Decoder decode_dlta()

{
  "id": "79191eec7b968dc126d17dd1fe423e1bf4d657e08f89e40e46102c9d4f10ac99",
  "url": "https://osv.dev/vulnerability/CVE-2026-58049",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "FFmpeg - Out-of-Bounds Write in RASC Decoder decode_dlta()",
    "summary": "FFmpeg's RASC video decoder (decode_dlta in libavcodec/rasc.c) performs 32-bit reads and writes at the row cursor before the NEXT_LINE row-boundary check and validates the DLTA region in pixel rather than byte units, so a DLTA run on a PAL8 frame can access several bytes past the row allocation. A crafted media stream using the RASC FourCC, decoded by libavcodec, triggers a bitstream-controlled out-of-bounds heap write and adjacent out-of-bounds read, leading to memory corruption.",
    "evidence": "osv:CVE-2026-58049",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-58049",
      "aliases": [
        "CVE-2026-58049"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/ffmpeg/ffmpeg",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "bcd2c69e087a09b07cf45c6bd2428ee1ccb2925c"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "bcd2c69e087a09b07cf45c6bd2428ee1ccb2925c"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  }
                ]
              }
            }
          ],
          "versions": [
            "n9.1-dev",
            "n8.2-dev",
            "n8.1-dev",
            "n7.2-dev",
            "n7.1-dev",
            "n6.2-dev",
            "n6.1-dev",
            "n5.2-dev",
            "n5.1-dev",
            "n4.5-dev",
            "n4.4-dev",
            "n4.3-dev",
            "n4.2-dev",
            "n4.1-dev",
            "n3.5-dev",
            "n3.4-dev",
            "n3.3-dev",
            "n3.2-dev",
            "n3.1-dev",
            "n2.9-dev",
            "n2.8-dev",
            "n2.7-dev",
            "n2.6-dev",
            "n2.5-dev",
            "n2.4-dev",
            "n2.3-dev",
            "n2.2-dev",
            "n2.0",
            "n2.1-dev",
            "n1.3-dev",
            "n1.2-dev",
            "n1.1-dev",
            "n0.12-dev",
            "n0.11-dev",
            "n0.8",
            "N"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-58049.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:51.364291582Z",
      "provider": "osv",
      "references": [
        "https://github.com/FFmpeg/FFmpeg/blob/master/libavcodec/rasc.c",
        "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-58049.json",
        "https://access.redhat.com/errata/RHSA-2026:43711",
        "https://access.redhat.com/errata/RHSA-2026:51180",
        "https://access.redhat.com/errata/RHSA-2026:52832",
        "https://access.redhat.com/errata/RHSA-2026:52833",
        "https://access.redhat.com/errata/RHSA-2026:60520",
        "https://access.redhat.com/errata/RHSA-2026:61627",
        "https://access.redhat.com/errata/RHSA-2026:61628",
        "https://access.redhat.com/errata/RHSA-2026:61629",
        "https://access.redhat.com/security/cve/CVE-2026-58049",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/58xxx/CVE-2026-58049.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-58049",
        "https://www.vulncheck.com/advisories/ffmpeg-out-of-bounds-write-in-rasc-decoder-decode-dlta",
        "https://bugzilla.redhat.com/show_bug.cgi?id=2493952",
        "https://github.com/bikini/exploitarium/tree/main/ffmpeg-rasc-dlta-calc-poc"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-787"
        ],
        "cna_assigner": "VulnCheck",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/58xxx/CVE-2026-58049.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-58049",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 519852,
  "published_at": "2026-06-28T01:32:52.9+00:00"
}