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No exploitation reportedFix available

CVE-2026-5673

Libtheora: libtheora: denial of service or information disclosure via malformed avi file processing

No exploitation reported by the sources we read.

  • Published2026-04-06
  • WeaknessCWE-125

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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.

Timeline

dates in UTC
  1. 2026-04-0609:22CVE publishedCNA

Versions per branch

NVD
Redhat enterprise linux
BranchAffectedFixed in
6.0= 6.0no fix published
7.0= 7.0no fix published
8.0= 8.0no fix published
9.0= 9.0no fix published
10.0= 10.0no fix published
Xiph theora
BranchAffectedFixed in
—all versionsno fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Products declared by the CNA5 products

As redhat, the CNA that assigned this CVE, declared them in the CVE record; versions as written.

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2026-11-05

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • ascUbuntu:26.10all versions · no fixed version listedand 2 other packages
  • ascUbuntu:26.04:LTSall versions · no fixed version listedand 2 other packages
  • ascUbuntu:25.10all versions · no fixed version listedand 2 other packages
  • ascUbuntu:24.04:LTSall versions · no fixed version listedand 1 other package
  • ascUbuntu:22.04:LTSall versions · no fixed version listedand 2 other packages
  • ascUbuntu:20.04:LTSall versions · no fixed version listedand 2 other packages
  • ascUbuntu:18.04:LTSall versions · no fixed version listedand 2 other packages
  • ascUbuntu:16.04:LTSall versions · no fixed version listedand 2 other packages

12 more package ranges on OSV.dev

Full record on NVD

Fix

No fix published by the sources we read yet. NVD record

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof of concept
Metasploit modules
none listed
Metasploit Framework

Sources

  • CISA-ADPSSVC decisionnone2026-04-06
  • CNACVSS 3.15.62026-11-05
  • NVDCVSS 3.17.1read 2026-11-05
  • CNAweakness (CWE)CWE-1252026-11-05
  • FIRST EPSSEPSS score0.2 %2026-11-08
  • OSVaffected packages—

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H
Published
2026-04-06
Last Modified
2026-11-05
NVD status
Analyzed

Frequently asked questions

What is CVE-2026-5673?

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.

Is CVE-2026-5673 actively exploited?

Active exploitation of CVE-2026-5673 has not been confirmed. Its EPSS score was 0.2% on 2026-11-08, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-5673?

CVE-2026-5673 has a CVSS v3 base score of 7.1 (HIGH severity), with vector string CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H.

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