CVE-2026-125218

EUVD-2026-120307
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-stream, causing APNG_DISPOSE_OP_BACKGROUND memset writes past prev_frame and crashing or corrupting heap memory in transcoding applications.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
VulnCheckCNA
7 HIGH
LOCAL
HIGH
NONE
CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources (CNA/ADP records, vendor advisories, Enginsight analysis).
VendorProductVersionSource
ffmpegffmpeg
𝑥
≤ 9.0.2
CNA
Common Weakness Enumeration
References
https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25682
https://github.com/FFmpeg/FFmpeg
https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/pngenc.c#L1148
https://github.com/FFmpeg/FFmpeg/commit/9b99973b2bbecee0b7e1e57035b95498b42f54a6
https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-apng-encoder-heap-buffer-overflow-via-encode-apng