FFmpeg before 8.1.3 and 9.x before 9.0.2 Heap Out-of-Bounds Write via APAC Decoder
Affects FFmpeg before 8.1.3 and 9.x before 9.0.2 through the APAC decoder in libavcodec/apac.c. Fixed in FFmpeg 8.1.3 and 9.0.2.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 8.1.3, 9.0.2
- Who is exposed
- Specific setups only
Do first: Check whether your setup matches what the bug needs. FFmpeg before 8.1.3, or 9.x before 9.0.2 Uses the APAC decoder in libavcodec/apac.c with an unreset bitstream index
- Last modified
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 14/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Specific setups only
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
FFmpeg before 8.1.3 and 9.x before 9.0.2 contains a heap out-of-bounds write vulnerability in the APAC decoder in libavcodec/apac.c caused by an unreset bitstream index. Attackers can supply a crafted APAC file whose growing bitstream_index triggers an integer overflow, bypassing the reallocation check so memcpy() corrupts heap memory or crashes the application.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure5/25Specific setups only
- Reach?/20Unknown. No tracked technology or package matched
- Severity8.5/10CVSS 8.5
- No patch0/5No signal
What would change the score
- Would score about 64 if added to CISA KEV
- Would score about 59 if CISA's SSVC rates exploitation active
- Would score about 24 if CISA's SSVC rates it automatable
What to do
Check whether your setup matches what the bug needs.
FFmpeg before 8.1.3, or 9.x before 9.0.2 Uses the APAC decoder in libavcodec/apac.c with an unreset bitstream indexUpgrade to a fixed version: 8.1.3, 9.0.2.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- FFmpeg FFmpeg
fixed in 8.1.3; From 9.0 · fixed in 9.0.2
Evidence 5
- Patch
- Report
- Repository
- Repository
- Link
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-125267
Is CVE-2026-125267 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
What does this mean?
The APAC decoder does not reset a bitstream index. An integer overflow then bypasses the reallocation check, so memcpy() writes past a heap buffer, which can corrupt heap memory or crash the application.Source: vulncheck.com
Which versions are affected by CVE-2026-125267?
FFmpeg: before 8.1.3; from 9.0 before 9.0.2.Source: cve.now feed data
Am I affected, and how do I check?
FFmpeg versions before 8.1.3, and 9.x versions before 9.0.2, are affected when the APAC decoder in libavcodec/apac.c is involved. To check, run ffmpeg -version and compare the version number with these ranges.Source: vulncheck.com
How do I fix CVE-2026-125267?
Upgrade to FFmpeg 8.1.3 for the 8.x line or to FFmpeg 9.0.2 for the 9.x line.Source: vulncheck.com