CVE-2026-76781 PUBLISHED

Libxml2: libxml2: null pointer dereference parsing nextcatalog without catalog attribute

Assigner: redhat
Reserved: 19.08.2026 Published: 17.09.2026 Updated: 18.09.2026

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).

Metrics

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
CVSS Score: 5.5

Product Status

Vendor Red Hat
Product Red Hat Enterprise Linux 10
Versions Default: affected
Vendor Red Hat
Product Red Hat Enterprise Linux 10
Versions Default: affected
Vendor Red Hat
Product Red Hat Enterprise Linux 6
Versions Default: unknown
Vendor Red Hat
Product Red Hat Enterprise Linux 7
Versions Default: unknown
Vendor Red Hat
Product Red Hat Enterprise Linux 8
Versions Default: affected
Vendor Red Hat
Product Red Hat Enterprise Linux 8
Versions Default: affected
Vendor Red Hat
Product Red Hat Enterprise Linux 8
Versions Default: affected
Vendor Red Hat
Product Red Hat Enterprise Linux 9
Versions Default: affected
Vendor Red Hat
Product Red Hat Enterprise Linux 9
Versions Default: affected
Vendor Red Hat
Product Red Hat Hardened Images
Versions Default: affected
Vendor Red Hat
Product Red Hat Hardened Images
Versions Default: unaffected
Vendor Red Hat
Product Red Hat OpenShift Container Platform 4
Versions Default: affected
Vendor Red Hat
Product Red Hat OpenShift Container Platform 4
Versions Default: affected
Vendor Red Hat
Product Red Hat OpenShift Container Platform 4
Versions Default: affected

Workarounds

To mitigate this issue, avoid processing untrusted XML catalog files with applications linked against libxml2. Users should exercise caution when opening or processing XML documents from untrusted sources, as a malicious catalog could lead to application crashes. Where possible, restrict the ability of applications to load external XML catalogs, or ensure that only trusted catalog files are used.

Credits

  • Red Hat would like to thank Yirou Yang for reporting this issue.

References

Problem Types

  • NULL Pointer Dereference CWE