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CVE-2026-66038

CVE-2026-66038 · FFmpeg LCL/ZLIB Video Decoder Information Disclosure via lcldec.c

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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.

CVSS 7.1 · High · EPSS 0.2% · Fix available

Published
Updated

Stack: system

Affected products and versions

  • ffmpeg

    Versions
    • ≥ 0, ≤ 8.1.2: Affected (semver)
    • 86708357d126af84c16f80d9c57335d1e8c845c5: Not affected (git)

    No fix published

  • ffmpeg Debian:12

    Versions
    • 7:5.1.3-1
    • 7:5.1.3-2
    • 7:5.1.4-0+deb12u1
    • 7:5.1.5-0+deb12u1
    • 7:5.1.6-0+deb12u1
    • 7:5.1.7-0+deb12u1
    • 7:5.1.8-0+deb12u1
    • 7:5.1.9-0+deb12u1
    • 7:6.0-1
    • 7:6.0-2
    • 7:6.0-3
    • 7:6.0-4
    • 7:6.0-5
    • 7:6.0-6
    • 7:6.0-7
    • 7:6.0-8
    • 7:6.0-9
    • 7:6.1-1
    • 7:6.1-2
    • 7:6.1-3
    • 7:6.1-4
    • 7:6.1-5
    • 7:6.1.1-1
    • 7:6.1.1-2
    • 7:6.1.1-3
    • 7:6.1.1-4
    • 7:6.1.1-5
    • 7:7.0-1
    • 7:7.0.1-1
    • 7:7.0.1-2
    • 7:7.0.1-3
    • 7:7.0.1-4
    • 7:7.0.1-5
    • 7:7.0.2-1
    • 7:7.0.2-2
    • 7:7.0.2-3
    • 7:7.1-1
    • 7:7.1-2
    • 7:7.1-3
    • 7:7.1-4
    • 7:7.1.1-1
    • 7:7.1.2-1
    • 7:7.1.3-1
    • 7:8.0-1
    • 7:8.0-2
    • 7:8.0.1-1
    • 7:8.0.1-2
    • 7:8.0.1-3
    • 7:8.1-1
    • 7:8.1-2
    • 7:8.1-3
    • 7:8.1.1-1
    • 7:8.1.1-2
    • 7:8.1.1-3
    • 7:8.1.1-4
    • 7:8.1.2-1
    • 7:8.1.2-2
    • 7:9.0-1
    • 7:9.0.1-1
    • 7:9.0.2-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • ffmpeg Debian:13

    Versions
    • 7:7.1.1-1
    • 7:7.1.2-0+deb13u1
    • 7:7.1.2-1
    • 7:7.1.3-0+deb13u1
    • 7:7.1.3-1
    • 7:7.1.4-0+deb13u1
    • 7:7.1.5-0+deb13u1
    • 7:8.0-1
    • 7:8.0-2
    • 7:8.0.1-1
    • 7:8.0.1-2
    • 7:8.0.1-3
    • 7:8.1-1
    • 7:8.1-2
    • 7:8.1-3
    • 7:8.1.1-1
    • 7:8.1.1-2
    • 7:8.1.1-3
    • 7:8.1.1-4
    • 7:8.1.2-1
    • 7:8.1.2-2
    • 7:9.0-1
    • 7:9.0.1-1
    • 7:9.0.2-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • ffmpeg Debian:14

    Versions
    • 7:7.1.1-1
    • 7:7.1.2-1
    • 7:7.1.3-1
    • 7:8.0-1
    • 7:8.0-2
    • 7:8.0.1-1
    • 7:8.0.1-2
    • 7:8.0.1-3
    • 7:8.1-1
    • 7:8.1-2
    • 7:8.1-3
    • 7:8.1.1-1
    • 7:8.1.1-2
    • 7:8.1.1-3
    • 7:8.1.1-4
    • 7:8.1.2-1
    • 7:8.1.2-2
    • 7:9.0-1
    • 7:9.0.1-1
    Affected ranges
    • ECOSYSTEM: < 7:9.0.2-1

    Update to 7:9.0.2-1

  • libav Ubuntu:Pro:14.04:LTS

    Versions
    • 6:0.8.7-1ubuntu2
    • 6:9.10-1ubuntu1
    • 6:9.10-1ubuntu2
    • 6:9.10-1ubuntu5
    • 6:9.10-1ubuntu6
    • 6:9.10-1ubuntu7
    • 6:9.11-2ubuntu1
    • 6:9.11-2ubuntu2
    • 6:9.13-0ubuntu0.14.04.1
    • 6:9.14-0ubuntu0.14.04.1
    • 6:9.16-0ubuntu0.14.04.1
    • 6:9.18-0ubuntu0.14.04.1
    • 6:9.20-0ubuntu0.14.04.1
    • 6:9.20-0ubuntu0.14.04.1+esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • ffmpeg Ubuntu:Pro:16.04:LTS

    Versions
    • 7:2.7.2-1build1
    • 7:2.8.1-1ubuntu1
    • 7:2.8.2-1ubuntu1
    • 7:2.8.3-1
    • 7:2.8.4-1
    • 7:2.8.4-1ubuntu1
    • 7:2.8.4-1ubuntu2
    • 7:2.8.4-1ubuntu3
    • 7:2.8.4-1ubuntu4
    • 7:2.8.6-1ubuntu1
    • 7:2.8.6-1ubuntu2
    • 7:2.8.8-0ubuntu0.16.04.1
    • 7:2.8.10-0ubuntu0.16.04.1
    • 7:2.8.11-0ubuntu0.16.04.1
    • 7:2.8.14-0ubuntu0.16.04.1
    • 7:2.8.15-0ubuntu0.16.04.1
    • 7:2.8.15-0ubuntu0.16.04.1+esm1
    • 7:2.8.17-0ubuntu0.1
    • 7:2.8.17-0ubuntu0.1+esm1
    • 7:2.8.17-0ubuntu0.1+esm2
    • 7:2.8.17-0ubuntu0.1+esm3
    • 7:2.8.17-0ubuntu0.1+esm4
    • 7:2.8.17-0ubuntu0.1+esm5
    • 7:2.8.17-0ubuntu0.1+esm6
    • 7:2.8.17-0ubuntu0.1+esm7
    • 7:2.8.17-0ubuntu0.1+esm8
    • 7:2.8.17-0ubuntu0.1+esm9
    • 7:2.8.17-0ubuntu0.1+esm10
    • 7:2.8.17-0ubuntu0.1+esm11
    • 7:2.8.17-0ubuntu0.1+esm12
    • 7:2.8.17-0ubuntu0.1+esm13
    • 7:2.8.17-0ubuntu0.1+esm14
    Affected ranges
    • ECOSYSTEM: < 7:2.8.17-0ubuntu0.1+esm15

    Update to 7:2.8.17-0ubuntu0.1+esm15

  • ffmpeg Ubuntu:Pro:18.04:LTS

    Versions
    • 7:3.3.4-2
    • 7:3.3.4-2build3
    • 7:3.4-2ubuntu2
    • 7:3.4-4
    • 7:3.4-4build1
    • 7:3.4.1-1
    • 7:3.4.1-1build1
    • 7:3.4.2-1
    • 7:3.4.2-1build1
    • 7:3.4.2-2
    • 7:3.4.4-0ubuntu0.18.04.1
    • 7:3.4.6-0ubuntu0.18.04.1
    • 7:3.4.8-0ubuntu0.2
    • 7:3.4.11-0ubuntu0.1
    • 7:3.4.11-0ubuntu0.1+esm1
    • 7:3.4.11-0ubuntu0.1+esm2
    • 7:3.4.11-0ubuntu0.1+esm3
    • 7:3.4.11-0ubuntu0.1+esm4
    • 7:3.4.11-0ubuntu0.1+esm5
    • 7:3.4.11-0ubuntu0.1+esm6
    • 7:3.4.11-0ubuntu0.1+esm7
    • 7:3.4.11-0ubuntu0.1+esm8
    • 7:3.4.11-0ubuntu0.1+esm9
    • 7:3.4.11-0ubuntu0.1+esm10
    • 7:3.4.11-0ubuntu0.1+esm11
    • 7:3.4.11-0ubuntu0.1+esm12
    Affected ranges
    • ECOSYSTEM: < 7:3.4.11-0ubuntu0.1+esm13

    Update to 7:3.4.11-0ubuntu0.1+esm13

  • ffmpeg Ubuntu:Pro:20.04:LTS

    Versions
    • 7:4.1.4-1build2
    • 7:4.2.1-2
    • 7:4.2.1-2ubuntu1
    • 7:4.2.2-1build1
    • 7:4.2.2-1ubuntu1
    • 7:4.2.4-1ubuntu0.1
    • 7:4.2.4-1ubuntu0.1+esm1
    • 7:4.2.7-0ubuntu0.1
    • 7:4.2.7-0ubuntu0.1+esm1
    • 7:4.2.7-0ubuntu0.1+esm2
    • 7:4.2.7-0ubuntu0.1+esm3
    • 7:4.2.7-0ubuntu0.1+esm4
    • 7:4.2.7-0ubuntu0.1+esm5
    • 7:4.2.7-0ubuntu0.1+esm6
    • 7:4.2.7-0ubuntu0.1+esm7
    • 7:4.2.7-0ubuntu0.1+esm8
    • 7:4.2.7-0ubuntu0.1+esm9
    • 7:4.2.7-0ubuntu0.1+esm10
    • 7:4.2.7-0ubuntu0.1+esm11
    • 7:4.2.7-0ubuntu0.1+esm12
    • 7:4.2.7-0ubuntu0.1+esm13
    Affected ranges
    • ECOSYSTEM: < 7:4.2.7-0ubuntu0.1+esm14

    Update to 7:4.2.7-0ubuntu0.1+esm14

  • ffmpeg Ubuntu:Pro:22.04:LTS

    Versions
    • 7:4.4-6ubuntu5
    • 7:4.4.1-2ubuntu1
    • 7:4.4.1-3ubuntu1
    • 7:4.4.1-3ubuntu2
    • 7:4.4.1-3ubuntu3
    • 7:4.4.1-3ubuntu5
    • 7:4.4.2-0ubuntu0.22.04.1
    • 7:4.4.2-0ubuntu0.22.04.1+esm1
    • 7:4.4.2-0ubuntu0.22.04.1+esm2
    • 7:4.4.2-0ubuntu0.22.04.1+esm3
    • 7:4.4.2-0ubuntu0.22.04.1+esm4
    • 7:4.4.2-0ubuntu0.22.04.1+esm5
    • 7:4.4.2-0ubuntu0.22.04.1+esm6
    • 7:4.4.2-0ubuntu0.22.04.1+esm7
    • 7:4.4.2-0ubuntu0.22.04.1+esm8
    • 7:4.4.2-0ubuntu0.22.04.1+esm9
    • 7:4.4.2-0ubuntu0.22.04.1+esm10
    • 7:4.4.2-0ubuntu0.22.04.1+esm11
    • 7:4.4.2-0ubuntu0.22.04.1+esm12
    Affected ranges
    • ECOSYSTEM: < 7:4.4.2-0ubuntu0.22.04.1+esm13

    Update to 7:4.4.2-0ubuntu0.22.04.1+esm13

  • ffmpeg Ubuntu:Pro:24.04:LTS

    Versions
    • 7:6.0-6ubuntu1
    • 7:6.0-9ubuntu1
    • 7:6.1-2ubuntu1
    • 7:6.1-3ubuntu1
    • 7:6.1-4ubuntu1
    • 7:6.1-5ubuntu1
    • 7:6.1.1-1ubuntu1
    • 7:6.1.1-3ubuntu1
    • 7:6.1.1-3ubuntu5
    • 7:6.1.1-3ubuntu5+esm1
    • 7:6.1.1-3ubuntu5+esm2
    • 7:6.1.1-3ubuntu5+esm3
    • 7:6.1.1-3ubuntu5+esm4
    • 7:6.1.1-3ubuntu5+esm5
    • 7:6.1.1-3ubuntu5+esm6
    • 7:6.1.1-3ubuntu5+esm7
    • 7:6.1.1-3ubuntu5+esm8
    • 7:6.1.1-3ubuntu5+esm10
    Affected ranges
    • ECOSYSTEM: < 7:6.1.1-3ubuntu5+esm11

    Update to 7:6.1.1-3ubuntu5+esm11

  • ffmpeg Ubuntu:26.10

    Versions
    • 7:8.0.1-3ubuntu2
    • 7:8.1-3ubuntu3
    • 7:8.1.2-2ubuntu2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • ffmpeg Ubuntu:Pro:26.04:LTS

    Versions
    • 7:7.1.1-1ubuntu4
    • 7:7.1.2-1ubuntu3
    • 7:7.1.2-1ubuntu4
    • 7:7.1.3-1ubuntu1
    • 7:8.0.1-2ubuntu1
    • 7:8.0.1-3ubuntu1
    • 7:8.0.1-3ubuntu2
    • 7:8.0.1-3ubuntu2+esm1
    Affected ranges
    • ECOSYSTEM: < 7:8.0.1-3ubuntu2+esm3

    Update to 7:8.0.1-3ubuntu2+esm3

Original sources

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