CVE-2025-8732

What it actually does

Uncontrolled recursion in xmlParseSGMLCatalog when processing SGML catalogs leads to stack exhaustion and local denial of service.

Why it matters to the business

Rare potential for application or service crashes on affected Linux systems that still rely on legacy SGML catalogs; low operational urgency given maintainer assessment that untrusted catalogs are never used in practice.

How an attack unfolds

A local attacker supplies a specially crafted SGML catalog file to the xmlcatalog utility or any application linked against a vulnerable libxml2 build, triggering unbounded recursion that crashes the process.

How to fix it

Upgrade linux-lts (Alpaquita:stream) and linux-lts (Alpaquita:25) to version 6.12.41-r0 or later; discontinue use of SGML catalogs entirely.

How to confirm the fix worked

Confirm installed package versions match or exceed the listed fixed releases; attempt to parse a test SGML catalog known to trigger recursion on unpatched builds and verify no crash occurs.

Typical attack path

1. Locate a system running an affected libxml2 package that exposes the xmlcatalog tool or equivalent SGML parsing path.
2. Craft a malicious SGML catalog containing recursive entity references.
3. Invoke the vulnerable function locally with the crafted catalog.
4. Observe process crash due to stack exhaustion.

How to detect it

Monitor process crash logs for segmentation faults or stack overflow signals originating from libxml2 SGML parsing routines; review command-line invocations of xmlcatalog for unexpected catalog arguments.

What your security team should do

• Apply the 6.12.41-r0 package updates across all affected Alpaquita streams immediately.
• Audit any remaining SGML catalog usage and migrate to XML catalogs.
• Add package version checks to vulnerability scanning pipelines.
• Review local attack surface for xmlcatalog or libxml2-based SGML handling.