CVE-2026-125218
Description
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.
CVSS Base Scores
CVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
Affected Products
| Vendor | Product | Version | Status |
|---|---|---|---|
| FFmpeg | FFmpeg | 0 | affected |
Credits
- Joshua Rogers (AISLE Research)(finder)
- Michael Niedermayer(remediation developer)
References
- https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25682
- https://github.com/FFmpeg/FFmpeg/commit/9b99973b2bbecee0b7e1e57035b95498b42f54a6
- https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/pngenc.c#L1148
- https://github.com/FFmpeg/FFmpeg
- https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-apng-encoder-heap-buffer-overflow-via-encode-apng


