What is CVE-2026-6653?

CVE-2026-6653 is a critical-severity vulnerability in Gnome Libxml2, classified under Use After Free. CVSS score: 9.8/10. Published 2026-06-22.

How severe is CVE-2026-6653?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Use After Free in Gnome Libxml2

CVE-2026-6653

Use After Free in libxml2's xmlParseInternalSubset from GNOME libxml2 version 2.9.11 to 2.11.0 allows a remote attacker to cause a denial-of-service via maliciously crafted XML input with improper entity resolution handling.

Vulnerability class: Use-After-Free

EPSS: 0.004 (28.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Gnome Libxml2 — versions 2.9.11
Xmlsoft Libxml2

Weakness classification (CWE)

References

security@ubuntu.com (issue-tracking, Exploit, Third Party Advisory, Issue Tracking)
security@ubuntu.com (issue-tracking, Exploit, Patch, Issue Tracking)

Frequently asked questions

What is CVE-2026-6653?: CVE-2026-6653 is a critical-severity vulnerability in Gnome Libxml2, classified under Use After Free. CVSS score: 9.8/10. Published 2026-06-22.
How severe is CVE-2026-6653?: Critical severity. CVSS v3 base score is 9.8 out of 10.