VULNERABILITY INTELLIGENCE

CVE-2026-66038

CVSS score6.5 MEDIUM
EPSS probability0.24%
CISA KEVNot currently listed
Published2026-07-24
Last modified2026-08-07
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

Description

FFmpeg through 8.1.2, fixed in commit 8670835, contains an information disclosure vulnerability in the LCL/ZLIB video decoder that allows attackers to expose uninitialized heap memory by supplying a valid zlib stream that inflates to fewer bytes than the expected frame size. The zlib_decomp() function in lcldec.c treats short decompression as non-fatal and continues to the RGB24 conversion path, which copies a full frame's worth of rows from the allocation buffer using original frame dimensions, causing uninitialized heap contents including pointer-derived allocator bytes to be copied into the attacker-observable AVFrame output and potentially defeating ASLR in long-lived media processing services.

Weakness classification

  • disclosure@vulncheck.com: CWE-908

Primary references