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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| FFmpeg | FFmpeg | ≤ 8.1.2 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | ffmpeg | 7:9.0.2-1 | — |
| Debian 13 | ffmpeg | No fix yet | — |
| Debian 12 | ffmpeg | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | ffmpeg | No fix yet | — |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 26.04 LTS | ffmpeg | 7:8.0.1-3ubuntu2+esm3 | USN-8738-1 |
| Ubuntu Pro 24.04 LTS | ffmpeg | 7:6.1.1-3ubuntu5+esm11 | USN-8671-1 |
| Ubuntu Pro 22.04 LTS | ffmpeg | 7:4.4.2-0ubuntu0.22.04.1+esm13 | USN-8671-1 |
| Ubuntu Pro 20.04 LTS | ffmpeg | 7:4.2.7-0ubuntu0.1+esm14 | USN-8671-1 |
| Ubuntu Pro 18.04 LTS | ffmpeg | 7:3.4.11-0ubuntu0.1+esm13 | USN-8671-1 |
| Ubuntu Pro 16.04 LTS | ffmpeg | 7:2.8.17-0ubuntu0.1+esm15 | USN-8671-1 |
| Ubuntu Pro 14.04 LTS | libav | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | ffmpeg-4 | 4.4.8-150600.13.52.1 | SUSE-SU-2026:3542-1 |
| SLES 15 SP4 | ffmpeg-4 | 4.4.8-150400.3.72.1 | SUSE-SU-2026:3529-1 |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | ffmpeg-7 | 7.1.4-160000.3.1 | SUSE-SU-2026:23232-1, SUSE-SU-2026:23222-1 |
| SLES for SAP 15 SP4 | ffmpeg-4 | 4.4.8-150400.3.72.1 | SUSE-SU-2026:3529-1 |
| SLES 16.0 | ffmpeg-7 | 7.1.4-160000.3.1 | SUSE-SU-2026:23232-1, SUSE-SU-2026:23222-1 |
| SLE HPC 15 SP4 | ffmpeg-4 | 4.4.8-150400.3.72.1 | SUSE-SU-2026:3529-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | ffmpeg-4 | 4.4.8-3.1 | openSUSE-SU-2026:11448-1 |
| openSUSE Tumbleweed | ffmpeg-7 | 7.1.5-2.1 | openSUSE-SU-2026:11665-1 |
| openSUSE Leap 16.0 | ffmpeg-4 | 4.4.7-bp160.3.1 | openSUSE-SU-2026:21522-1 |
| openSUSE Leap 16.0 | ffmpeg-7 | 7.1.4-160000.3.1 | openSUSE-SU-2026:21572-1 |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | ffmpeg-7 +2 | No fix yet | — |
| Wolfi rolling | ffmpeg-8.1 | 8.1.3-r0 | — |
Advisories 11
- WID-SEC-2026-2526 ffmpeg: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 12, 2026
- USN-8738-1 ffmpeg vulnerabilities Ubuntu Security Notices (USN) · Sep 10, 2026
- openSUSE-SU-2026:11665-1 ffmpeg-7-7.1.5-2.1 on GA media SUSE / openSUSE Security Updates · Sep 3, 2026
- SUSE-SU-2026:23232-1 Security update for ffmpeg-7 SUSE / openSUSE Security Updates · Aug 27, 2026
- SUSE-SU-2026:23222-1 Security update for ffmpeg-7 SUSE / openSUSE Security Updates · Aug 27, 2026
- USN-8671-1 ffmpeg vulnerabilities Ubuntu Security Notices (USN) · Aug 25, 2026
- openSUSE-SU-2026:21572-1 Security update for ffmpeg-7 SUSE / openSUSE Security Updates · Aug 14, 2026
- SUSE-SU-2026:3542-1 Security update for ffmpeg-4 SUSE / openSUSE Security Updates · Aug 11, 2026
- SUSE-SU-2026:3529-1 Security update for ffmpeg-4 SUSE / openSUSE Security Updates · Aug 8, 2026
- openSUSE-SU-2026:21522-1 Security update for ffmpeg-4 SUSE / openSUSE Security Updates · Aug 5, 2026
- openSUSE-SU-2026:11448-1 ffmpeg-4-4.4.8-3.1 on GA media SUSE / openSUSE Security Updates · Aug 5, 2026
References
- Pull Request issue-tracking
- Patch Commit patch
- https://www.vulncheck.com/advisories/ffmpeg-lcl-zlib-video-decoder-information-disclosure-via-lcldec-c third-party-advisory