CVE-2026-5673

Publication date 7 April 2026

Last updated 7 April 2026

Ubuntu priority

Cvss 3 Severity Score

Description

A flaw was found in libtheora. This heap-based out-of-bounds read vulnerability exists within the AVI (Audio Video Interleave) parser, specifically in the avi_parse_input_file() function. A local attacker could exploit this by tricking a user into opening a specially crafted AVI file containing a truncated header sub-chunk. This could lead to a denial-of-service (application crash) or potentially leak sensitive information from the heap.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
asc	25.10 questing	Needs evaluation
	24.04 LTS noble	Needs evaluation
	22.04 LTS jammy	Needs evaluation
	20.04 LTS focal	Needs evaluation
	18.04 LTS bionic	Needs evaluation
	16.04 LTS xenial	Needs evaluation
libtheora	25.10 questing	Needs evaluation
	24.04 LTS noble	Needs evaluation
	22.04 LTS jammy	Needs evaluation
	20.04 LTS focal	Needs evaluation
	18.04 LTS bionic	Needs evaluation
	16.04 LTS xenial	Needs evaluation
mkvtoolnix	25.10 questing	Needs evaluation
	24.04 LTS noble	Needs evaluation
	22.04 LTS jammy	Needs evaluation
	20.04 LTS focal	Needs evaluation
	18.04 LTS bionic	Needs evaluation
	16.04 LTS xenial	Needs evaluation
ogmrip	25.10 questing	Needs evaluation
	24.04 LTS noble	Not in release
	22.04 LTS jammy	Needs evaluation
	20.04 LTS focal	Needs evaluation
	18.04 LTS bionic	Needs evaluation
	16.04 LTS xenial	Needs evaluation

Notes

rodrigo-zaiden

bug seems to be in avilib, which is also included in ogmrip, mkvtoolnix, and asc packages, which could be also affected if there is no prevetion code before calling avilib.

Severity score breakdown

Parameter	Value
Base score	5.6 · Medium
Attack vector	Local
Attack complexity	Low
Privileges required	Low
User interaction	Required
Scope	Unchanged
Confidentiality	Low
Integrity impact	None
Availability impact	High
Vector	CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:H