CVE-2026-0990: Libxml2: libxml2: denial of service via uncontrolled recursion in xml catalog processing

Published Jan 15, 2026
·
Updated

A flaw was found in libxml2, an XML parsing library. This uncontrolled recursion vulnerability occurs in the xmlCatalogXMLResolveURI function when an XML catalog contains a delegate URI entry that references itself. A remote attacker could exploit this configuration-dependent issue by providing a specially crafted XML catalog, leading to infinite recursion and call stack exhaustion. This ultimately results in a segmentation fault, causing a Denial of Service (DoS) by crashing affected applications.

Affected Software

4 affected componentsFixes available
libxml2 libxml2
Microsoft cbl2 libxml2 2.10.4-10
Microsoft azl3 libxml2 2.11.5-8
Microsoft azl3 libxml2 2.11.5-9

Event History

Jan 15, 2026
Data Sourced
via Red Hat·01:19 PM
DescriptionSeverityAffected Software
CVE Published
via MITRE·02:20 PM
Data Sourced
via MITRE·02:20 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·03:15 PM
DescriptionSeverityWeakness
Jan 19, 2026
Data Sourced
via Microsoft·09:01 AM
DescriptionSeverityWeaknessAffected Software
Updated
via Microsoft·09:01 AM
Affected Software
Updated
via Microsoft·09:01 AM
DescriptionSeverity
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Frequently Asked Questions

1

What is the severity of CVE-2026-0990?

The severity of CVE-2026-0990 has been rated as high due to its potential to cause denial of service.

2

How do I fix CVE-2026-0990?

To fix CVE-2026-0990, update to the latest version of libxml2 that addresses this vulnerability.

3

What causes CVE-2026-0990?

CVE-2026-0990 is caused by uncontrolled recursion in the xmlCatalogXMLResolveURI function during XML catalog processing.

4

Who is affected by CVE-2026-0990?

All users of libxml2 that handle XML catalogs with delegate URI entries may be affected by CVE-2026-0990.

5

How can I test for CVE-2026-0990?

You can test for CVE-2026-0990 by attempting to process an XML catalog that includes recursive delegate URI entries and observing for any denial of service conditions.

Contact

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