CVE-2026-70631FFmpeg 0.5 < 9.0 Uninitialized Heap Memory Read in TIFF Decoder
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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FFmpeg versions from 0.5 up to, but not including, 9.0 contain an uninitialized heap memory disclosure vulnerability in the native TIFF decoder in libavcodec/tiff.c. An attacker who can cause FFmpeg to decode a crafted TIFF file can supply a valid Deflate-compressed strip that terminates successfully after producing fewer bytes than the declared strip requires. The tiff_unpack_zlib() function allocates a heap buffer sized for the full declared strip but copies all declared rows via memcpy() regardless of how many bytes zlib actually decompressed, causing unwritten bytes that can contain stale data from prior heap allocations to be incorporated into decoded image output and potentially exposing sensitive data in persistent services.
- CVSS
- 5.5 MEDIUM (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
- Weakness (CWE)
- CWE-908
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- VulnCheck
- NVD analysis
- Analyzed
- Record last updated
- Aug 14, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
FFmpeg FFmpeg ffmpeg:ffmpeg (from the name) | from 0.5 before 9.0 | CNA record |
ffmpeg ffmpeg ffmpeg:ffmpeg | from 0.5 before 9 | NVD |
References
- https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23899issue-tracking, patch
- https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/a991b1fecbd8c9e6f4fc31c191bd12e4be27dbf7related, patch
- https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/2f234ea34c81288e3840fca632dd16481d8de39fpatch
- https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/3c287af3affe1286350faa69c02bcc5d49de18bbpatch
- https://www.vulncheck.com/advisories/ffmpeg-uninitialized-heap-memory-read-in-tiff-decoderthird-party-advisory, patch
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.