CVE-2026-76781: Null Dereference (CVSS 5.5)

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).

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CVSS v3.1 Score

5.5

MEDIUM

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

EPSS — Exploit Prediction

0.0017

Probability of exploitation

0.06%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-476 CWE-476

References

Other 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

Frequently Asked Questions

What is CVE-2026-76781? +

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). It has a CVSS v3.1 base score of 5.5 (MEDIUM).

How severe is CVE-2026-76781? +

CVE-2026-76781 has a CVSS v3.1 score of 5.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0017, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-76781? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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