5.6
MEDIUM CVSS 3.1
CVE-2026-5673
Libtheora: libtheora: denial of service or information disclosure via malformed avi file processing
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.

INFO

Published Date :

April 6, 2026, 10:16 a.m.

Last Modified :

April 6, 2026, 10:16 a.m.

Remotely Exploit :

No
Affected Products

The following products are affected by CVE-2026-5673 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM 53f830b8-0a3f-465b-8143-3b8a9948e749
CVSS 3.1 MEDIUM [email protected]
CVSS 3.1 MEDIUM MITRE-CVE
Solution
Update libtheora to the latest version to fix heap-based out-of-bounds read.
  • Update libtheora to the patched version.
  • Avoid opening untrusted AVI files.
  • Validate AVI file integrity before processing.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-5673.

URL Resource
https://access.redhat.com/security/cve/CVE-2026-5673
https://bugzilla.redhat.com/show_bug.cgi?id=2455340
https://github.com/xiph/theora/issues/24
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-5673 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-5673 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-5673 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-5673 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Apr. 06, 2026

    Action Type Old Value New Value
    Added 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.
    Added CVSS V3.1 AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:H
    Added CWE CWE-125
    Added Reference https://access.redhat.com/security/cve/CVE-2026-5673
    Added Reference https://bugzilla.redhat.com/show_bug.cgi?id=2455340
    Added Reference https://github.com/xiph/theora/issues/24
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.