FFmpeg up to 8.1.2/9.0.1 APAC decoder libavcodec/apac.c memcpy integer overflow

Summaryinfo

A vulnerability, which was classified as critical, has been found in FFmpeg up to 8.1.2/9.0.1. The affected element is the function memcpy of the file libavcodec/apac.c of the component APAC decoder. Performing a manipulation results in integer overflow. This vulnerability is cataloged as CVE-2026-125267. It is possible to initiate the attack remotely. There is no exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in FFmpeg up to 8.1.2/9.0.1. It has been classified as critical. This affects the function memcpy of the file libavcodec/apac.c of the component APAC decoder. The manipulation with an unknown input leads to a integer overflow vulnerability. CWE is classifying the issue as CWE-190. The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at code.ffmpeg.org. This vulnerability is uniquely identified as CVE-2026-125267 since 11/09/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available.

Upgrading to version 8.1.3 or 9.0.2 eliminates this vulnerability.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Multimedia Processing Software

Name

• FFmpeg

Version

• 8.1.0
• 8.1.1
• 8.1.2
• 9.0.0
• 9.0.1

License

• open-source

Website

• Product: https://ffmpeg.org/

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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