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.

CVSS v3 5.5 MEDIUM

5.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.8 / Impact : 3.6

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact HIGH

Integrity Impact NONE

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24856
https://github.com/FFmpeg/FFmpeg
https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/cdxl.c#L226-L229
https://github.com/FFmpeg/FFmpeg/commit/47313ad3f9f33b892384b976fb7c09b3c85fd74e
https://www.vulncheck.com/advisories/ffmpeg-4.4-through-9.0.2-uninitialized-memory-disclosure-via-cdxl-ham-decoder

Configurations

No configuration.

History

01 Nov 2026, 01:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-11-01 01:17

Updated : 2026-11-02 19:34

NVD link : CVE-2026-120246

Mitre link : CVE-2026-120246

CVE.ORG link : CVE-2026-120246

JSON object : View

Products Affected

No product.

CWE

CWE-457

Use of Uninitialized Variable

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