Buffer overflow in Ffmpeg
CVE-2026-64835
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.
Vulnerability class: Buffer Overflow
EPSS: 0.003 (25.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.
Affected products
- Ffmpeg — versions 4.4, 1836ef96846937a6cc2443698a693104f5c0b21e
Weakness classification (CWE)
References
- disclosure@vulncheck.com (issue-tracking, Patch, Issue Tracking)
- disclosure@vulncheck.com (Patch, patch)
- disclosure@vulncheck.com (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-64835?
- CVE-2026-64835 is a high-severity vulnerability in Ffmpeg, classified under Out-of-bounds Write. CVSS score: 8.8/10. Published 2026-07-22.
- How severe is CVE-2026-64835?
- High severity. CVSS v3 base score is 8.8 out of 10.