OESA-2026-4809

FFmpeg is a complete and free Internet live audio and video broadcasting solution for Linux/Unix. It also includes a digital VCR. It can encode in real time in many formats including MPEG1 audio and video, MPEG4, h263, ac3, asf, avi, real, mjpeg, and flash.

Security Fix(es):

FFmpeg through 9.0.2 contains a stack exhaustion vulnerability in av_encryption_init_info_free() in libavutil/encryption_info.c, which recursively frees AVEncryptionInitInfo linked lists built by the MOV demuxer's mov_read_pssh(). Attackers can supply a crafted MP4 file with tens of thousands of small pssh boxes to exhaust the stack and crash the process, while also causing quadratic CPU consumption.(CVE-2026-107678)

FFmpeg 2.0 through 9.0.2 contains a use of uninitialized variable vulnerability in the Go2Meeting decoder that allows attackers to leak stack memory through out-of-range palette indices. Attackers can craft a G2M3/G2M4 stream with a short Kempf palette so kempf_restore_buf() copies uninitialized stack bytes, including pointers or stack guards, into decoded output.(CVE-2026-120243)

FFmpeg 2.1 through 9.0.2 contains a use of uninitialized resource vulnerability in the PCX decoder that allows attackers to leak heap memory through truncated RLE scanlines. Attackers can craft a PCX image whose RLE data ends early, causing pcx_decode_frame() to copy uninitialized av_malloc() buffer contents into visible decoded pixels.(CVE-2026-120244)

FFmpeg 0.10 through 9.0.2 contains a use of uninitialized resource vulnerability in sunrast_decode_frame() that leaks heap memory when decoding truncated 1-bit and 4-bit paletted Sun Raster images. Attackers can craft a truncated Sun Raster file so the uncleared temporary bitmap is expanded into PAL8 pixels, exposing stale heap contents such as allocator words in decoded output.(CVE-2026-120245)

FFmpeg 4.4 through 9.0.2 contains a use of uninitialized variable vulnerability in the CDXL decoder that leaks stack memory into decoded pixels via unfilled HAM palette entries. Attackers can craft a type-0 CDXL file whose HAM pixels select unfilled new_palette entries in cdxl_decode_ham8() or cdxl_decode_ham6(), exposing stack bytes and pointer fragments in the BGR24 output.(CVE-2026-120246)

FFmpeg 2.3 through 9.0.2 contains a use of uninitialized resource vulnerability in the Huffyuv decoder that allows attackers to leak heap memory into decoded pixels via short packed-BGR bitstreams. Attackers can craft a Huffyuv BGR24/BGRA video whose entropy data ends early, causing decode_slice() to add uninitialized s->temp[0] bytes into output frames, exposing heap contents.(CVE-2026-120247)