Vulnerability record/PUBLISHED/Published Nov 9, 2026 19:10:57 UTC

CVE-2026-125103

FFmpeg through 9.0.2 contains an information disclosure vulnerability in ff_mlz_decompression() in libavcodec/mlz.c, which accepts string codes beyond the dictionary's next free code. Attackers can supply a crafted MPEG-4 ALS file with malformed initial or out-of-range codes to copy uninitialized heap bytes into decoded audio output.

Base score4.8/ 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 confidentialityLowVC

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:L/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 10, 2026 15:47:52 UTC

PublishedNov 9, 2026 19:10:57 UTC

ReservedNov 9, 2026 17:44:25 UTC

Credits

Joshua Rogers (AISLE Research)
Michael Niedermayer