Bug 2494693

Summary: CVE-2026-11979 pcem: libxml2: Arbitrary code execution in xmlcatalog utility via buffer overflow [fedora-all]
Product: [Fedora] Fedora Reporter: Jon Moroney <jmoroney>
Component: pcemAssignee: Michel Lind <michel>
Status: CLOSED NOTABUG QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: 45CC: davide
Target Milestone: ---Keywords: Reopened, Security, SecurityTracking
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["0fb04d31-b419-4aff-96c6-b4eca863f51a"]}
Fixed In Version: Doc Type: ---
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2026-10-06 13:42:31 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 2443016, 2494191    

Description Jon Moroney 2026-06-29 21:05:08 UTC
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

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.

Comment 1 Aoife Moloney 2026-08-17 15:06:05 UTC
This bug appears to have been reported against 'rawhide' during the Fedora Linux 45 development cycle.
Changing version to 45.

Comment 2 Michel Lind 2026-10-06 13:42:31 UTC
The tool affected by the CVE is not shipped by this source RPM's binary subpackages