CVE-2026-64831

Publication date 22 July 2026

Last updated 28 August 2026

Ubuntu priority

Cvss 3 Severity Score

Description

FFmpeg versions 8.0 through 8.1.2 contains a stack buffer overflow vulnerability in the Vulkan HEVC hardware decoder that allows remote attackers to overwrite return addresses and adjacent stack frames by supplying a crafted HEVC/H.265 bitstream. Attackers can embed a malicious vps_num_hrd_parameters value exceeding HEVC_MAX_SUB_LAYERS in any supported container format to overflow stack-allocated arrays in the vk_hevc_end_frame function, potentially achieving arbitrary code execution.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
ffmpeg	26.04 LTS resolute	Vulnerable
	24.04 LTS noble	Not affected
	22.04 LTS jammy	Not affected
	20.04 LTS focal	Not affected
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not affected
libav	26.04 LTS resolute	Not in release
	24.04 LTS noble	Not in release
	22.04 LTS jammy	Not in release
	14.04 LTS trusty	Needs evaluation

Notes

leosilva

CVE-2026-64831: xenial/bionic/focal/jammy/noble not-affected vulkan_hevc.c vulnerable inline stack arrays introduced in 8.0 (commit 82864c2); releases < 8.0 lack the vulnerable code path.

Severity score breakdown

CVSS version:

Base score 8.7 · High

Base metrics

Parameter	Value
Attack vector	Network
Attack complexity	Low
Attack requirements	None
Privileges required	None
User interaction	Passive
Vulnerable system - Confidentiality impact	High
Vulnerable system - Integrity impact	High
Vulnerable system - Availability impact	High
Subsequent system - Confidentiality impact	None
Subsequent system - Integrity impact	None
Subsequent system - Availability impact	None

Scores

Parameter	Value
Base score	8.7 · High
Base + Threat score	-
Base + Environmental score	-
Base + Threat + Environmental score	-

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Base score 8.8 · High