Application crash via mismatched SAX callback context
Published Apr 23, 2026 · Updated Apr 23, 2026
Type confusion in libxml2 2.13.0 through 2.15.2 allows attackers to crash XSD-validating applications via crafted XML documents. xmlParseReference passes xmlParserCtxt instead of ctxt->userData to SAX text callbacks, causing an active xmlSchemaSAXPlug handler to interpret the parser context as its own callback state. The path requires an internal entity reference in an XSD-validated document and produces a reliable application SIGSEGV without reported data disclosure or modification.
Summary
What happened
Type confusion in libxml2 2.13.0 through 2.15.2 allows attackers to crash XSD-validating applications via crafted XML documents. xmlParseReference passes xmlParserCtxt instead of ctxt->userData to SAX text callbacks, causing an active xmlSchemaSAXPlug handler to interpret the parser context as its own callback state. The path requires an internal entity reference in an XSD-validated document and produces a reliable application SIGSEGV without reported data disclosure or modification.
The record
- CVE
- CVE-2026-6732
- Published
- Apr 23, 2026
- Updated
- Apr 23, 2026
- Vendor
- 389 Directory Server
- Product
- Red Hat JBoss Core Services
- Classifications
- CWE-843, T1499
- Attack vector
- adjacent
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 23, 2026CVE publishedPublication date reported by the CVE source.
- Apr 23, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- GNOME libxml2 issue 1097 reproducerproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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