FFmpeg up to 8.1.2 ADX Decoder libavcodec/adxdec.c adx_decode_frame prev out-of-bounds

Summaryinfo

A vulnerability identified as critical has been detected in FFmpeg up to 8.1.2. This impacts the function adx_decode_frame of the file libavcodec/adxdec.c of the component ADX Decoder. The manipulation of the argument prev leads to out-of-bounds. This vulnerability is documented as CVE-2026-64835. The attack can be initiated remotely. There is not any exploit available.

Detailsinfo

A vulnerability was found in FFmpeg up to 8.1.2. It has been rated as critical. This issue affects the function adx_decode_frame of the file libavcodec/adxdec.c of the component ADX Decoder. The manipulation of the argument prev with an unknown input leads to a out-of-bounds vulnerability. Using CWE to declare the problem leads to CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

FFmpeg versions 4.4 through 8.1.2 contain an out-of-bounds memory access vulnerability in the ADX audio decoder within libavcodec/adxdec.c that allows attackers to trigger both out-of-bounds reads and writes by supplying a crafted ADX or AAX audio file with a mid-stream channel layout change. When AV_PKT_DATA_NEW_EXTRADATA side data is received mid-stream, the adx_decode_frame function re-parses the stream header but fails to update the internal channel state, causing subsequent decoding operations to access the prev[] state array using a stale channel count.

It is possible to read the advisory at code.ffmpeg.org. The identification of this vulnerability is CVE-2026-64835 since 07/20/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 07/22/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

• Multimedia Processing Software

Name

• FFmpeg

Version

• 8.1.0
• 8.1.1
• 8.1.2

License

• open-source

Website

• Product: https://ffmpeg.org/

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