FFmpeg Heap Buffer Overflow via RIST Protocol Reader

{
  "id": "407346a4939f5004d92cd945b605d9aa51c8ea63e8369cae2f17236d6d181aa3",
  "url": "https://www.cve.org/CVERecord?id=CVE-2026-75143",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "FFmpeg Heap Buffer Overflow via RIST Protocol Reader",
    "summary": "FFmpeg before commit 1c10bcc contains a heap buffer overflow in the RIST protocol reader (libavformat/librist.c). librist_read() ignored its size argument and copied the full received payload length into the caller-provided destination buffer, overflowing it when the payload exceeds the destination size. This is reachable via the async:rist:// URL scheme, where the async wrapper supplies a smaller buffer than the received payload. A remote RIST sender can trigger the overflow by sending a packet whose payload exceeds the caller buffer size.",
    "evidence": "cve:CVE-2026-75143",
    "products": [
      {
        "name": {
          "value": "FFmpeg",
          "evidence": "/containers/cna/affected/0/product"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": []
      }
    ],
    "severity": "critical",
    "structured": {
      "id": "CVE-2026-75143",
      "aliases": [
        "CVE-2026-75143"
      ],
      "metrics": [
        {
          "format": "CVSS",
          "cvssV4_0": {
            "Safety": "NOT_DEFINED",
            "version": "4.0",
            "Recovery": "NOT_DEFINED",
            "baseScore": 9.3,
            "Automatable": "NOT_DEFINED",
            "attackVector": "NETWORK",
            "baseSeverity": "CRITICAL",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
            "exploitMaturity": "NOT_DEFINED",
            "providerUrgency": "NOT_DEFINED",
            "userInteraction": "NONE",
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "privilegesRequired": "NONE",
            "subIntegrityImpact": "NONE",
            "vulnIntegrityImpact": "HIGH",
            "subAvailabilityImpact": "NONE",
            "vulnAvailabilityImpact": "HIGH",
            "subConfidentialityImpact": "NONE",
            "vulnConfidentialityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
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        {
          "format": "CVSS",
          "cvssV3_1": {
            "scope": "UNCHANGED",
            "version": "3.1",
            "baseScore": 9.8,
            "attackVector": "NETWORK",
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "integrityImpact": "HIGH",
            "userInteraction": "NONE",
            "attackComplexity": "LOW",
            "availabilityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "confidentialityImpact": "HIGH"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "affected": [
        {
          "repo": "https://code.ffmpeg.org/FFmpeg/FFmpeg",
          "vendor": "FFmpeg",
          "product": "FFmpeg",
          "versions": [
            {
              "status": "affected",
              "version": "0",
              "lessThan": "1c10bcc2e17255dacb717a25ab3db142ce390602",
              "versionType": "git"
            }
          ],
          "packageURL": "pkg:github/FFmpeg/FFmpeg",
          "defaultStatus": "unaffected"
        }
      ],
      "modified": "2026-10-27T10:14:30.888Z",
      "provider": "cve",
      "references": [
        "https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24089",
        "https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/1c10bcc2e17255dacb717a25ab3db142ce390602",
        "https://www.vulncheck.com/advisories/ffmpeg-heap-buffer-overflow-via-rist-protocol-reader"
      ],
      "provider_metadata": {
        "adp": [
          {
            "title": "CISA ADP Vulnrichment",
            "metrics": [
              {
                "other": {
                  "type": "ssvc",
                  "content": {
                    "id": "CVE-2026-75143",
                    "role": "CISA Coordinator",
                    "options": [
                      {
                        "Exploitation": "none"
                      },
                      {
                        "Automatable": "yes"
                      },
                      {
                        "Technical Impact": "total"
                      }
                    ],
                    "version": "2.0.3",
                    "timestamp": "2026-08-20T00:00:00+00:00"
                  }
                }
              }
            ],
            "providerMetadata": {
              "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "shortName": "CISA-ADP",
              "dateUpdated": "2026-08-21T03:55:45.266Z"
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        "cna": {
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          "shortName": "VulnCheck",
          "dateUpdated": "2026-10-27T10:14:30.888Z"
        }
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    },
    "related_cves": [
      {
        "value": "CVE-2026-75143",
        "evidence": "/cveMetadata/cveId"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/containers/cna/metrics"
  },
  "source_id": "core-cve",
  "document_id": 391794,
  "published_at": "2026-08-19T16:26:12.445+00:00"
}