GHSA-MJXR-6GQF-W78H

Vulnerability from github – Published: 2026-06-28 03:33 – Updated: 2026-09-01 15:30
VLAI
Details

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.

Severity
8.6 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H
8.8 (High)
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
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{
  "affected": [],
  "aliases": [
    "CVE-2026-58049"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-787"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-06-28T02:16:30Z",
    "severity": "HIGH"
  },
  "details": "FFmpeg\u0027s 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.",
  "id": "GHSA-mjxr-6gqf-w78h",
  "modified": "2026-09-01T15:30:49Z",
  "published": "2026-06-28T03:33:40Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-58049"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:43711"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:51180"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:52832"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:52833"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:60520"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:61627"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:61628"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:61629"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/security/cve/CVE-2026-58049"
    },
    {
      "type": "WEB",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2493952"
    },
    {
      "type": "WEB",
      "url": "https://github.com/FFmpeg/FFmpeg/blob/master/libavcodec/rasc.c"
    },
    {
      "type": "WEB",
      "url": "https://github.com/bikini/exploitarium/tree/main/ffmpeg-rasc-dlta-calc-poc"
    },
    {
      "type": "WEB",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-58049.json"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/ffmpeg-out-of-bounds-write-in-rasc-decoder-decode-dlta"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H",
      "type": "CVSS_V3"
    },
    {
      "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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
      "type": "CVSS_V4"
    }
  ]
}



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