Vulnerability Description
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 Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Xmlsoft | Libxml2 | <= 2.15.3 |
Related Weaknesses (CWE)
References
- https://cert.pl/en/posts/2026/06/CVE-2026-11979Third Party Advisory
- https://gitlab.gnome.org/GNOME/libxml2/-/commit/c2e233fc1b341685fc99621b2768b503Patch
FAQ
What is CVE-2026-11979?
CVE-2026-11979 is a vulnerability with a CVSS score of 7.8 (HIGH). 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 with...
How severe is CVE-2026-11979?
CVE-2026-11979 has been rated HIGH with a CVSS base score of 7.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-11979?
Check the references section above for vendor advisories and patch information. Affected products include: Xmlsoft Libxml2.