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

Status: published. Published: 2026-09-17. Updated: 2026-11-06.

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).

## Remediation

- workaround: 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. (source: CNA: redhat)

## Affected products and versions

- Red Hat / Red Hat Hardened Images (libxml2-main): ≥ 2.15.3-0.1.3.hum1; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 10 (libxml2): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 10 (podman): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 6 (libxml2): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 7 (libxml2): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8 (container-tools:rhel8/podman): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8 (libxml2): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8 (podman): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9 (libxml2): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9 (podman): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Hardened Images (swift-lang): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4 (openshift/ose-rhel-coreos-8): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4 (openshift/ose-rhel-coreos-9): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4 (podman): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 5 (openshift/ose-rhel-coreos-9): Version range not reported. Source: CNA: redhat

## Severity and prioritization

- CVSS 3.1: 5.5 (medium); CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H; source: CNA: redhat

- CISA KEV: No listing in collected sources

- EPSS: 0.16% as of 2026-11-05; percentile 4.93%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-476

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://access.redhat.com/errata/RHSA-2026:57604 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/security/cve/CVE-2026-76781 (CNA: redhat; vdb-entry, x_refsource_REDHAT)

- https://bugzilla.redhat.com/show_bug.cgi?id=2519776 (CNA: redhat; issue-tracking, x_refsource_REDHAT)

- https://gitlab.gnome.org/GNOME/libxml2/-/commit/c6324894 (CNA: redhat)

- https://gitlab.gnome.org/GNOME/libxml2/-/merge_requests/442 (CNA: redhat)

## Provenance

- CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2026-76781; retrieved 2026-11-06; source updated 2026-11-06

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-76781; retrieved 2026-11-06; source updated Not reported

Revision: 2333e7a8dcd4856e8c05f9b2bcf7b95f691d9cd81116aa7a279737cf51c42780

Canonical: https://y2.dev/cve/CVE-2026-76781

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