Description
FFmpeg versions from 0.5 up to, but not including, 9.0 contain a signed integer overflow vulnerability in the DVB subtitle parser in libavcodec/dvbsub_parser.c that allows attackers to trigger a heap buffer overflow by supplying a crafted WTV file. The overflow causes the bounds-check guard expression to wrap to INT_MIN, bypassing the PARSE_BUF_SIZE comparison and invoking memcpy() with attacker-controlled data into a heap buffer, resulting in an out-of-bounds heap write and potential memory corruption or code execution.
Affected products
ffmpeg: ffmpeg
References5
- code.ffmpeg.org/FFmpeg/FFmpeg/commit/02fc47e13f903768b75f7985a2… Patch
- code.ffmpeg.org/FFmpeg/FFmpeg/commit/93f2a525ec6c7b467bae683227… Patch
- code.ffmpeg.org/FFmpeg/FFmpeg/commit/c6ec28b18cd1eb7d39e6163137… Patch
- code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23897 Issue TrackingPatch
- www.vulncheck.com/advisories/ffmpeg-dvb-subtitle-parser-heap-bu… PatchThird Party Advisory
Metrics
- CVSS 3.1
-
7.8
HIGH
Score source: CNA
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - CVSS 4.0
-
8.5
HIGH
Score source: CNA
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 0% percentile: 4 · as of 12 November 2026
- CWE
- CWE-190CWE-787
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.