High severity · published Apr 6, 2026
CVE-2026-5673
Libtheora: libtheora: denial of service or information disclosure via malformed avi file processing
7.1
CVSS
0.2%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H
Attack vector
Local
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
High
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 7% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
RH
Red Hat Enterprise Linux 10 · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat Enterprise Linux 6 · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat Enterprise Linux 7 · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat Enterprise Linux 8 · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat Enterprise Linux 9 · Red Hat
All versions, or not specified · source: vendor
EL
Enterprise Linux · Redhat
6.0; 7.0; 8.0; 9.0; 10.0 · source: NVD
TH
Theora · Xiph
All versions, or not specified · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-5673
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-5673
Third Party Advisory
https://access.redhat.com/security/cve/CVE-2026-5673
Issue Tracking
https://bugzilla.redhat.com/show_bug.cgi?id=2455340
Exploit
https://github.com/xiph/theora/issues/24
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