{"id":"CVE-2026-66038","summary":"FFmpeg LCL/ZLIB Video Decoder Information Disclosure via lcldec.c","details":"FFmpeg through 8.1.2, fixed in commit 8670835, contains an information disclosure vulnerability in the LCL/ZLIB video decoder that allows attackers to expose uninitialized heap memory by supplying a valid zlib stream that inflates to fewer bytes than the expected frame size. The zlib_decomp() function in lcldec.c treats short decompression as non-fatal and continues to the RGB24 conversion path, which copies a full frame's worth of rows from the allocation buffer using original frame dimensions, causing uninitialized heap contents including pointer-derived allocator bytes to be copied into the attacker-observable AVFrame output and potentially defeating ASLR in long-lived media processing services.","modified":"2026-08-12T03:51:20.242157495Z","published":"2026-07-24T19:39:27.448Z","related":["SUSE-SU-2026:3529-1","SUSE-SU-2026:3542-1","openSUSE-SU-2026:11448-1","openSUSE-SU-2026:21522-1"],"database_specific":{"cwe_ids":["CWE-908"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/66xxx/CVE-2026-66038.json","unresolved_ranges":[{"extracted_events":[{"last_affected":"8.1.2"}],"source":"AFFECTED_FIELD"},{"extracted_events":[{"last_affected":"8.1.2"}],"source":"CPE_FIELD"},{"extracted_events":[{"fixed":"8.1.2"}],"source":"DESCRIPTION"}],"cna_assigner":"VulnCheck"},"references":[{"type":"WEB","url":"https://code.ffmpeg.org/FFmpeg/FFmpeg"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/66xxx/CVE-2026-66038.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-66038"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/ffmpeg-lcl-zlib-video-decoder-information-disclosure-via-lcldec-c"},{"type":"REPORT","url":"https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23626"},{"type":"FIX","url":"https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/e7cbfd1c507b57a806a5825b87d609963e862c8c"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/ffmpeg/ffmpeg","events":[{"introduced":"0"},{"last_affected":"38b88335f99e76ed89ff3c93f877fdefce736c13"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"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","n2.0","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-2026-66038.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N"}]}