Buffer overflow in Ffmpeg
CVE-2026-58049
FFmpeg's RASC video decoder (decode_dlta in libavcodec/rasc.c) performs 32-bit reads and writes at the row cursor before the NEXT_LINE row-boundary check and validates the DLTA region in pixel rather than byte units, so a DLTA run on a PAL8 frame can access several bytes past the row allocation. A crafted media stream using the RASC FourCC, decoded by libavcodec, triggers a bitstream-controlled out-of-bounds heap write and adjacent out-of-bounds read, leading to memory corruption.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H.
EPSS exploit prediction
EPSS: 0.005 (40.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 40th percentile — 40.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.002
Affected products
- Ffmpeg — versions 0
Weakness classification (CWE)
References
- github.com/FFmpeg/FFmpeg/blob/master/libavcodec/rasc.c (product)
- github.com/bikini/exploitarium/tree/main/ffmpeg-rasc-dlta-calc-poc (exploit, third-party-advisory)
- www.vulncheck.com/advisories/ffmpeg-out-of-bounds-write-in-rasc-decoder-decode-… (third-party-advisory)
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Frequently asked questions
- What is CVE-2026-58049?
- CVE-2026-58049 is a high-severity vulnerability in Ffmpeg, classified under Out-of-bounds Write. CVSS score: 8.6/10. Published 2026-06-28.
- How severe is CVE-2026-58049?
- High severity. CVSS v3 base score is 8.6 out of 10.