CVE-2026-120246
FFmpeg 4.4 through 9.0.2 Uninitialized Memory Disclosure via CDXL HAM Decoder
FFmpeg 4.4 through 9.0.2 contains a use of uninitialized variable vulnerability in the CDXL decoder that leaks stack memory into decoded pixels via unfilled HAM palette entries. Attackers can craft a type-0 CDXL file whose HAM pixels select unfilled new_palette entries in cdxl_decode_ham8() or cdxl_decode_ham6(), exposing stack bytes and pointer fragments in the BGR24 output.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Passive
What an attacker can affect
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
FFmpeg 4.4 through 9.0.2 Uninitialized Memory Disclosure via CDXL HAM Decoder
FFmpeg 4.4 through 9.0.2 contains a use of uninitialized variable vulnerability in the CDXL decoder that leaks stack memory into decoded pixels via unfilled HAM palette entries. Attackers can craft a type-0 CDXL file whose HAM pixels select unfilled new_palette entries in cdxl_decode_ham8() or cdxl_decode_ham6(), exposing stack bytes and pointer fragments in the BGR24 output.
- Record
CVE-2026-120246- CVSS 4.0
- 6.8 Medium
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N - CVSS 3.1
- 5.5 Medium
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N - Weakness
- CWE-457
- Updated
- 2026-11-05
EUVDEUVD-2026-114743
FFmpeg 4.4 through 9.0.2 contains a use of uninitialized variable vulnerability in the CDXL decoder that leaks stack memory into decoded pixels via unfilled HAM palette entries. Attackers can craft a type-0 CDXL file whose HAM pixels select unfilled new_palette entries in cdxl_decode_ham8() or cdxl_decode_ham6(), exposing stack bytes and pointer fragments in the BGR24 output.
- Record
EUVD-2026-114743- CVSS 4.0
- 6.8 Medium
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N - Updated
- 2026-11-05
GitHub AdvisoriesGHSA-76cq-jhfp-r489
FFmpeg 4.4 through 9.0.2 contains a use of uninitialized variable vulnerability in the CDXL...
FFmpeg 4.4 through 9.0.2 contains a use of uninitialized variable vulnerability in the CDXL decoder that leaks stack memory into decoded pixels via unfilled HAM palette entries. Attackers can craft a type-0 CDXL file whose HAM pixels select unfilled new_palette entries in cdxl_decode_ham8() or cdxl_decode_ham6(), exposing stack bytes and pointer fragments in the BGR24 output.
- Record
GHSA-76cq-jhfp-r489- CVSS 4.0
- 6.8 Medium
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 5.5 Medium
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N - Weakness
- CWE-457
- Updated
- 2026-11-02
NVD
FFmpeg 4.4 through 9.0.2 contains a use of uninitialized variable vulnerability in the CDXL decoder that leaks stack memory into decoded pixels via unfilled HAM palette entries. Attackers can craft a type-0 CDXL file whose HAM pixels select unfilled new_palette entries in cdxl_decode_ham8() or cdxl_decode_ham6(), exposing stack bytes and pointer fragments in the BGR24 output.
- Record
CVE-2026-120246- CVSS 4.0
- 6.8 Medium
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 5.5 Medium
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N - Weakness
- CWE-457
- Updated
- 2026-11-05
OSV
FFmpeg 4.4 through 9.0.2 Uninitialized Memory Disclosure via CDXL HAM Decoder
FFmpeg 4.4 through 9.0.2 contains a use of uninitialized variable vulnerability in the CDXL decoder that leaks stack memory into decoded pixels via unfilled HAM palette entries. Attackers can craft a type-0 CDXL file whose HAM pixels select unfilled new_palette entries in cdxl_decode_ham8() or cdxl_decode_ham6(), exposing stack bytes and pointer fragments in the BGR24 output.
- Record
CVE-2026-120246- CVSS 4.0
- 6.8 Medium
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-457
- Updated
- 2026-11-07
OSVDEBIAN-CVE-2026-120246
FFmpeg 4.4 through 9.0.2 contains a use of uninitialized variable vulnerability in the CDXL decoder that leaks stack memory into decoded pixels via unfilled HAM palette entries. Attackers can craft a type-0 CDXL file whose HAM pixels select unfilled new_palette entries in cdxl_decode_ham8() or cdxl_decode_ham6(), exposing stack bytes and pointer fragments in the BGR24 output.
- Record
DEBIAN-CVE-2026-120246- CVSS 4.0
- 6.8 Medium
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Updated
- 2026-11-06
OSVUBUNTU-CVE-2026-120246
FFmpeg 4.4 through 9.0.2 contains a use of uninitialized variable vulnerability in the CDXL decoder that leaks stack memory into decoded pixels via unfilled HAM palette entries. Attackers can craft a type-0 CDXL file whose HAM pixels select unfilled new_palette entries in cdxl_decode_ham8() or cdxl_decode_ham6(), exposing stack bytes and pointer fragments in the BGR24 output.
- Record
UBUNTU-CVE-2026-120246- CVSS 4.0
- 6.8 Medium
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N - CVSS 3.1
- 5.5 Medium
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N - Updated
- 2026-11-05
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
ffmpegDebian:12 |
All versions, plus listed versions 7:5.1.3-17:5.1.3-27:5.1.4-0+deb12u17:5.1.5-0+deb12u17:5.1.6-0+deb12u1 Show 45 moreShow less7:5.1.7-0+deb12u17:5.1.8-0+deb12u17:5.1.9-0+deb12u17:6.0-17:6.0-27:6.0-37:6.0-47:6.0-57:6.0-67:6.0-77:6.0-87:6.0-97:6.1-17:6.1-27:6.1-37:6.1-47:6.1-57:6.1.1-17:6.1.1-27:6.1.1-37:6.1.1-47:6.1.1-57:7.0-17:7.0.1-17:7.0.1-27:7.0.1-37:7.0.1-47:7.0.1-57:7.0.2-17:7.0.2-27:7.0.2-37:7.1-17:7.1-27:7.1-37:7.1-47:7.1.1-17:7.1.2-17:7.1.3-17:8.0-17:8.0-27:8.0.1-17:8.0.1-27:8.0.1-37:8.1-17:8.1-2 |
None known |
ffmpegDebian:13 |
All versions, plus listed versions 7:7.1.1-17:7.1.2-0+deb13u17:7.1.2-17:7.1.3-0+deb13u17:7.1.3-1 Show 22 moreShow less7:7.1.4-0+deb13u17:7.1.5-0+deb13u17:8.0-17:8.0-27:8.0.1-17:8.0.1-27:8.0.1-37:8.1-17:8.1-27:8.1-37:8.1.1-17:8.1.1-27:8.1.1-37:8.1.1-47:8.1.2-17:8.1.2-27:9.0-17:9.0.1-17:9.0.2-17:9.0.2-27:9.0.2-37:9.0.2-4 |
None known |
ffmpegDebian:14 |
All versions, plus listed versions 7:7.1.1-17:7.1.2-17:7.1.3-17:8.0-17:8.0-2 Show 18 moreShow less7:8.0.1-17:8.0.1-27:8.0.1-37:8.1-17:8.1-27:8.1-37:8.1.1-17:8.1.1-27:8.1.1-37:8.1.1-47:8.1.2-17:8.1.2-27:9.0-17:9.0.1-17:9.0.2-17:9.0.2-27:9.0.2-37:9.0.2-4 |
None known |
libavUbuntu:Pro:14.04:LTS |
All versions, plus listed versions 6:0.8.7-1ubuntu26:9.10-1ubuntu16:9.10-1ubuntu26:9.10-1ubuntu56:9.10-1ubuntu6 Show 9 moreShow less6:9.10-1ubuntu76:9.11-2ubuntu16:9.11-2ubuntu26:9.13-0ubuntu0.14.04.16:9.14-0ubuntu0.14.04.16:9.16-0ubuntu0.14.04.16:9.18-0ubuntu0.14.04.16:9.20-0ubuntu0.14.04.16:9.20-0ubuntu0.14.04.1+esm1 |
None known |
ffmpegUbuntu:Pro:16.04:LTS |
All versions, plus listed versions 7:2.7.2-1build17:2.8.1-1ubuntu17:2.8.2-1ubuntu17:2.8.3-17:2.8.4-1 Show 31 moreShow less7:2.8.4-1ubuntu17:2.8.4-1ubuntu27:2.8.4-1ubuntu37:2.8.4-1ubuntu47:2.8.6-1ubuntu17:2.8.6-1ubuntu27:2.8.8-0ubuntu0.16.04.17:2.8.10-0ubuntu0.16.04.17:2.8.11-0ubuntu0.16.04.17:2.8.14-0ubuntu0.16.04.17:2.8.15-0ubuntu0.16.04.17:2.8.15-0ubuntu0.16.04.1+esm17:2.8.17-0ubuntu0.17:2.8.17-0ubuntu0.1+esm17:2.8.17-0ubuntu0.1+esm27:2.8.17-0ubuntu0.1+esm37:2.8.17-0ubuntu0.1+esm47:2.8.17-0ubuntu0.1+esm57:2.8.17-0ubuntu0.1+esm67:2.8.17-0ubuntu0.1+esm77:2.8.17-0ubuntu0.1+esm87:2.8.17-0ubuntu0.1+esm97:2.8.17-0ubuntu0.1+esm107:2.8.17-0ubuntu0.1+esm117:2.8.17-0ubuntu0.1+esm127:2.8.17-0ubuntu0.1+esm137:2.8.17-0ubuntu0.1+esm147:2.8.17-0ubuntu0.1+esm157:2.8.17-0ubuntu0.1+esm167:2.8.17-0ubuntu0.1+esm177:2.8.17-0ubuntu0.1+esm18 |
None known |
ffmpegUbuntu:Pro:18.04:LTS |
All versions, plus listed versions 7:3.3.4-27:3.3.4-2build37:3.4-2ubuntu27:3.4-47:3.4-4build1 Show 25 moreShow less7:3.4.1-17:3.4.1-1build17:3.4.2-17:3.4.2-1build17:3.4.2-27:3.4.4-0ubuntu0.18.04.17:3.4.6-0ubuntu0.18.04.17:3.4.8-0ubuntu0.27:3.4.11-0ubuntu0.17:3.4.11-0ubuntu0.1+esm17:3.4.11-0ubuntu0.1+esm27:3.4.11-0ubuntu0.1+esm37:3.4.11-0ubuntu0.1+esm47:3.4.11-0ubuntu0.1+esm57:3.4.11-0ubuntu0.1+esm67:3.4.11-0ubuntu0.1+esm77:3.4.11-0ubuntu0.1+esm87:3.4.11-0ubuntu0.1+esm97:3.4.11-0ubuntu0.1+esm107:3.4.11-0ubuntu0.1+esm117:3.4.11-0ubuntu0.1+esm127:3.4.11-0ubuntu0.1+esm137:3.4.11-0ubuntu0.1+esm147:3.4.11-0ubuntu0.1+esm157:3.4.11-0ubuntu0.1+esm16 |
None known |
ffmpegUbuntu:Pro:20.04:LTS |
All versions, plus listed versions 7:4.1.4-1build27:4.2.1-27:4.2.1-2ubuntu17:4.2.2-1build17:4.2.2-1ubuntu1 Show 21 moreShow less7:4.2.4-1ubuntu0.17:4.2.4-1ubuntu0.1+esm17:4.2.7-0ubuntu0.17:4.2.7-0ubuntu0.1+esm17:4.2.7-0ubuntu0.1+esm27:4.2.7-0ubuntu0.1+esm37:4.2.7-0ubuntu0.1+esm47:4.2.7-0ubuntu0.1+esm57:4.2.7-0ubuntu0.1+esm67:4.2.7-0ubuntu0.1+esm77:4.2.7-0ubuntu0.1+esm87:4.2.7-0ubuntu0.1+esm97:4.2.7-0ubuntu0.1+esm107:4.2.7-0ubuntu0.1+esm117:4.2.7-0ubuntu0.1+esm127:4.2.7-0ubuntu0.1+esm137:4.2.7-0ubuntu0.1+esm147:4.2.7-0ubuntu0.1+esm157:4.2.7-0ubuntu0.1+esm167:4.2.7-0ubuntu0.1+esm177:4.2.7-0ubuntu0.1+esm18 |
None known |
ffmpegUbuntu:Pro:22.04:LTS |
All versions, plus listed versions 7:4.4-6ubuntu57:4.4.1-2ubuntu17:4.4.1-3ubuntu17:4.4.1-3ubuntu27:4.4.1-3ubuntu3 Show 19 moreShow less7:4.4.1-3ubuntu57:4.4.2-0ubuntu0.22.04.17:4.4.2-0ubuntu0.22.04.1+esm17:4.4.2-0ubuntu0.22.04.1+esm27:4.4.2-0ubuntu0.22.04.1+esm37:4.4.2-0ubuntu0.22.04.1+esm47:4.4.2-0ubuntu0.22.04.1+esm57:4.4.2-0ubuntu0.22.04.1+esm67:4.4.2-0ubuntu0.22.04.1+esm77:4.4.2-0ubuntu0.22.04.1+esm87:4.4.2-0ubuntu0.22.04.1+esm97:4.4.2-0ubuntu0.22.04.1+esm107:4.4.2-0ubuntu0.22.04.1+esm117:4.4.2-0ubuntu0.22.04.1+esm127:4.4.2-0ubuntu0.22.04.1+esm137:4.4.2-0ubuntu0.22.04.1+esm147:4.4.2-0ubuntu0.22.04.1+esm157:4.4.2-0ubuntu0.22.04.1+esm167:4.4.2-0ubuntu0.22.04.1+esm17 |
None known |
ffmpegUbuntu:Pro:24.04:LTS |
All versions, plus listed versions 7:6.0-6ubuntu17:6.0-9ubuntu17:6.1-2ubuntu17:6.1-3ubuntu17:6.1-4ubuntu1 Show 17 moreShow less7:6.1-5ubuntu17:6.1.1-1ubuntu17:6.1.1-3ubuntu17:6.1.1-3ubuntu57:6.1.1-3ubuntu5+esm17:6.1.1-3ubuntu5+esm27:6.1.1-3ubuntu5+esm37:6.1.1-3ubuntu5+esm47:6.1.1-3ubuntu5+esm57:6.1.1-3ubuntu5+esm67:6.1.1-3ubuntu5+esm77:6.1.1-3ubuntu5+esm87:6.1.1-3ubuntu5+esm107:6.1.1-3ubuntu5+esm117:6.1.1-3ubuntu5+esm127:6.1.1-3ubuntu5+esm137:6.1.1-3ubuntu5+esm15 |
None known |
ffmpegUbuntu:26.10 |
All versions, plus listed versions 7:8.0.1-3ubuntu27:8.1-3ubuntu37:8.1.2-2ubuntu2 |
None known |
ffmpegUbuntu:Pro:26.04:LTS |
All versions, plus listed versions 7:7.1.1-1ubuntu47:7.1.2-1ubuntu37:7.1.2-1ubuntu47:7.1.3-1ubuntu17:8.0.1-2ubuntu1 Show 6 moreShow less7:8.0.1-3ubuntu17:8.0.1-3ubuntu27:8.0.1-3ubuntu2+esm17:8.0.1-3ubuntu2+esm37:8.0.1-3ubuntu2+esm47:8.0.1-3ubuntu2+esm5 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, aliases, references | OSV | |
| facts | NVD, OSV | |
| affected, aliases, facts, references | OSV | |
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-120246 is a medium vulnerability (CVSS 6.8) in Ffmpeg, published November 1, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.12%, the 2nd percentile. No source names a fixed version.
References
code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24856
github.com/FFmpeg/FFmpeg/commit/47313ad3f9f33b892384b976fb7c09b3c85fd74e
vulncheck.com/advisories/ffmpeg-4.4-through-9.0.2-uninitialized-memory-disclosure-via-cdxl-ham-decoder
nvd.nist.gov/vuln/detail/CVE-2026-120246
Left out here: 13 versions. The JSON record has them.