What’s Vulnerable › Vulnerabilities

CVE-2026-76781: Libxml2: libxml2: null pointer dereference parsing nextcatalog without catalog attribute

• Severity: medium (CVSS 5.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-17 · updated 2026-10-30
• Weakness: CWE-476

Description

A flaw was found in libxml2. A local user or an attacker providing a specially crafted XML catalog can trigger a NULL pointer dereference during XML catalog parsing. This occurs when a `nextCatalog` element lacks its mandatory `catalog` attribute, leading to the application crashing and causing a Denial of Service (DoS).

Affected products

• Red Hat OpenShift Container Platform 4.18: all versions
• Red Hat Enterprise Linux 10: all versions
• Red Hat Enterprise Linux 8: all versions
• Red Hat Enterprise Linux 9: all versions
• Red Hat Hardened Images: all versions — fixed in 2.15.3-0.1.3.hum1
• Red Hat OpenShift Container Platform 5: all versions

How to fix

Upgrade to a fixed version: Red Hat Hardened Images 2.15.3-0.1.3.hum1. Check the vendor advisory for mitigations.

References

• https://access.redhat.com/errata/RHSA-2026:57604
• https://access.redhat.com/security/cve/CVE-2026-76781
• https://bugzilla.redhat.com/show_bug.cgi?id=2519776
• https://gitlab.gnome.org/GNOME/libxml2/-/commit/c6324894
• https://gitlab.gnome.org/GNOME/libxml2/-/merge_requests/442

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