{"id":"CVE-2026-64830","summary":"FFmpeg 2.1 - 8.1.2 Heap Buffer Overflow via VobSub Subtitle Demuxer","details":"FFmpeg versions 2.1 through 8.1.2 contains a heap buffer overflow vulnerability in the VobSub subtitle demuxer that allows attackers to corrupt adjacent heap memory by supplying a malicious .sub/.idx subtitle file declaring more distinct stream IDs than the fixed-size array bounds in libavformat/mpeg.c. Attackers can craft a subtitle file with excessive distinct stream IDs to trigger unbounded writes beyond the vobsub-\u003eq[] array boundary via ff_subtitles_queue_insert(), potentially achieving arbitrary code execution in any application using FFmpeg's VobSub demuxer.","modified":"2026-08-04T11:51:17.510856270Z","published":"2026-07-22T16:33:05.724Z","database_specific":{"unresolved_ranges":[{"source":"AFFECTED_FIELD","extracted_events":[{"introduced":"2.1"},{"last_affected":"8.1.2"},{"introduced":"dbd495f066a85ba96b17433f4306582aa37c3951"},{"last_affected":"dbd495f066a85ba96b17433f4306582aa37c3951"}]},{"source":"CPE_FIELD","extracted_events":[{"introduced":"2.1"},{"last_affected":"8.1.2"}]},{"extracted_events":[{"introduced":"2.1"},{"fixed":"8.1.2"}],"source":"DESCRIPTION"}],"cna_assigner":"VulnCheck","cwe_ids":["CWE-122"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64830.json"},"references":[{"type":"WEB","url":"https://code.ffmpeg.org/FFmpeg/FFmpeg"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64830.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64830"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/ffmpeg-heap-buffer-overflow-via-vobsub-subtitle-demuxer"},{"type":"REPORT","url":"https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23657"},{"type":"FIX","url":"https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/dbd495f066a85ba96b17433f4306582aa37c3951"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.ffmpeg.org/ffmpeg.git","events":[{"introduced":"a37e42b3ee4226a4d2c69cd4eebf9c81e6df8ea5"},{"last_affected":"38b88335f99e76ed89ff3c93f877fdefce736c13"}],"database_specific":{"extracted_events":[{"introduced":"2.1"},{"last_affected":"8.1.2"}],"source":"CPE_RANGE","cpe":"cpe:2.3:a:ffmpeg:ffmpeg:*:*:*:*:*:*:*:*"}}],"versions":["n8.1.2","n8.1.1","n8.1","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","n2.1-dev"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64830.json"}}],"schema_version":"1.8.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"}]}