Vulnerability record/PUBLISHED/Published Nov 1, 2026 00:57:11 UTC

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.

Base score6.8/ 10

SeverityMediumCVSS 4.0

Exploitability / impact

CVSS metric breakdown

Vector-derived attributes

Base severityMedium

Attack vectorLocalAV

Attack complexityLowAC

Attack requirementsNoneAT

Privileges requiredNonePR

User interactionPassiveUI

Vulnerable system confidentialityHighVC

Vulnerable system integrityNoneVI

Vulnerable system availabilityNoneVA

Subsequent system confidentialityNoneSC

Subsequent system integrityNoneSI

Subsequent system availabilityNoneSA

CVSS vector stringCVSS: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 communicates standardized severity and impact characteristics. It does not establish whether a system is exploitable in your specific environment.

Record context

CVE Numbering AuthorityVulnCheck

Last updatedNov 1, 2026 00:57:11 UTC

PublishedNov 1, 2026 00:57:11 UTC

ReservedOct 31, 2026 22:05:58 UTC

Credits

Adrian Junge (vurlo)