November 14, 2026

CVE Watchtower

CVE-2026-125267FFmpeg FFmpeg Integer Overflow or Wraparound

NVD

Vulnerability 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.
Severity Level
HIGH(8.5)
Published Date
Nov 9, 2026
Last Modified
Nov 10, 2026
Exploitation Status
No confirmed exploitation yet
EPSS Score (30-Day)
0.14%Probability
Root Weakness (CWE)
CWE-190: Integer Overflow or Wraparound ↗
The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes the resulting value will always be larger than the original.
CVSS v4.0 Base Metrics — Score 8.5 (HIGH)
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
Attack VectorLocal
Attack ComplexityLow
Attack RequirementsNone
Privileges RequiredNone
User InteractionPassive
Confidentiality (Vulnerable System)High
Integrity (Vulnerable System)High
Availability (Vulnerable System)High
Confidentiality (Subsequent System)None
Integrity (Subsequent System)None
Availability (Subsequent System)None
Show CVSS v3.x metrics (score 7.8)
CVSS v3.1 Base Metrics — Score 7.8 (HIGH)
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Attack VectorLocal
Attack ComplexityLow
Privileges RequiredNone
User InteractionRequired
ScopeUnchanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh

Affected & Patched Versions

Affected Versions
  • FFmpeg FFmpeg < 8.1.3
  • FFmpeg FFmpeg >= 9.0 and < 9.0.2
Patched Versions
  • FFmpeg FFmpeg 8.1.3
  • FFmpeg FFmpeg 9.0.2

What to do

Plan remediation soon. No exploitation is confirmed yet, but the severity is high.

  1. Check whether you run FFmpeg FFmpeg and which version.
  2. Update to a patched version listed above, then confirm the new version.

Timeline

  • Nov 9, 2026Published
  • Nov 10, 2026Record last modified

Score, severity and exploitation changes are tracked from the day Watchtower started logging them.

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External References

Data last checked: Nov 13, 2026 21:28 UTC