[xml/sgml-pkgs] Bug#1125691: libxml2: CVE-2026-0989: Deep RelaxNG Include Causes Stack Overflow

[Salvatore Bonaccorso]

Source: libxml2.9
Version: 2.15.1+dfsg-2
Severity: important
Tags: security upstream
Forwarded: https://gitlab.gnome.org/GNOME/libxml2/-/issues/998
X-Debbugs-Cc: carnil at debian.org, Debian Security Team <team at security.debian.org>

Hi,

The following vulnerability was published for libxml2.

CVE-2026-0989[0]:
| A flaw was identified in the RelaxNG parser of libxml2 related to
| how external schema inclusions are handled. The parser does not
| enforce a limit on inclusion depth when resolving nested <include>
| directives. Specially crafted or overly complex schemas can cause
| excessive recursion during parsing. This may lead to stack
| exhaustion and application crashes, creating a denial-of-service
| risk.


If you fix the vulnerability please also make sure to include the
CVE (Common Vulnerabilities & Exposures) id in your changelog entry.

For further information see:

[0] https://security-tracker.debian.org/tracker/CVE-2026-0989
    https://www.cve.org/CVERecord?id=CVE-2026-0989
[1] https://gitlab.gnome.org/GNOME/libxml2/-/issues/998

Please adjust the affected versions in the BTS as needed.

Regards,
Salvatore