{"id":"CVE-2026-125218","title":"FFmpeg through 9.0.2 APNG Encoder Heap Buffer Overflow via encode_apng()","summary":"FFmpeg through 9.0.2 contains a heap buffer overflow vulnerability in the APNG encoder's encode_apng() function in libavcodec/pngenc.c when frame size changes mid-stream. Attackers can supply crafted media whose resolution grows mid-stre…","severity":"high","cvss":7,"cvssVector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H","cvssSource":"cna","cwe":["CWE-122"],"vendor":"FFmpeg","product":"FFmpeg","affected":["FFmpeg <= 9.0.2"],"published":"2026-11-09","updated":"2026-11-09","sourceUpdated":"2026-11-09T19:11:33.101Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-125218","references":[{"url":"https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25682"},{"url":"https://github.com/FFmpeg/FFmpeg/commit/9b99973b2bbecee0b7e1e57035b95498b42f54a6","label":"Patch Commit"},{"url":"https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/pngenc.c#L1148"},{"url":"https://github.com/FFmpeg/FFmpeg"},{"url":"https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-apng-encoder-heap-buffer-overflow-via-encode-apng","label":"VulnCheck Advisory: FFmpeg through 9.0.2 APNG Encoder Heap Buffer Overflow via encode_apng()"}],"tags":["cve.org"],"ingestedAt":"2026-11-09T19:18:02.591Z","slug":"CVE-2026-125218","body":"## Overview\n\nFFmpeg through 9.0.2 contains a heap buffer overflow vulnerability in the APNG encoder's encode_apng() function in libavcodec/pngenc.c when frame size changes mid-stream. Attackers can supply crafted media whose resolution grows mid-stream, causing APNG_DISPOSE_OP_BACKGROUND memset writes past prev_frame and crashing or corrupting heap memory in transcoding applications.\n\n## Affected\n\n- `FFmpeg <= 9.0.2`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":38.5,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}