CVE-2026-11979

libxml2 is vulnerable to multiple stack-based buffer overflows in the xmlcatalog utility when running in --shell mode. The usershell() function processes user input using fixed-size stack buffers without proper bounds checking. By supplying an overly long input line, an attacker can overflow internal buffers (command, arg, and argv) during input parsing. This results in memory corruption within the stack frame. Successful exploitation may cause a crash or potentially allow arbitrary code execution in the context of the xmlcatalog process. This issue has been fixed in the commit c2e233fc. NOTE: The maintainers of this project did not agree that this issue is a vulnerability and considered it a bug.

CVSS v3 7.8 HIGH

7.8^/10

CVSS v3 : HIGH

Vector :

Exploitability : 1.8 / Impact : 5.9

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://cert.pl/en/posts/2026/06/CVE-2026-11979	Third Party Advisory
https://gitlab.gnome.org/GNOME/libxml2/-/commit/c2e233fc1b341685fc99621b2768b503f777a72e	Patch

Configurations

Configuration 1 (hide)

cpe:2.3:a:xmlsoft:libxml2:*:*:*:*:*:*:*:*

History

30 Jun 2026, 20:22

Type	Values Removed	Values Added
CPE		cpe:2.3:a:xmlsoft:libxml2::::::::
First Time		Xmlsoft libxml2 Xmlsoft
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 7.8
References	~~() https://cert.pl/en/posts/2026/06/CVE-2026-11979 -~~	() https://cert.pl/en/posts/2026/06/CVE-2026-11979 - Third Party Advisory
References	~~() https://gitlab.gnome.org/GNOME/libxml2/-/commit/c2e233fc1b341685fc99621b2768b503f777a72e -~~	() https://gitlab.gnome.org/GNOME/libxml2/-/commit/c2e233fc1b341685fc99621b2768b503f777a72e - Patch

29 Jun 2026, 14:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-06-29 14:16

Updated : 2026-06-30 20:22

NVD link : CVE-2026-11979

Mitre link : CVE-2026-11979

CVE.ORG link : CVE-2026-11979

JSON object : View

Products Affected

xmlsoft

libxml2

CWE

CWE-121

Stack-based Buffer Overflow

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