Application crash via unsafe comment-to-element cast
Published Mar 13, 2026 · Updated Mar 13, 2026
Type confusion in Lexbor before 2.7.0 allows remote attackers to crash applications that process crafted HTML fragments. When the fragment parser receives ns = UNDEF, it creates a comment with the unknown-element constructor, then unsafely casts the comment and writes its data into element fields, corrupting qualified_name. Exploitation requires an application to pass attacker-controlled HTML into fragment parsing; the corrupted field is later treated as a pointer and dereferenced near the zero page.
Summary
What happened
Type confusion in Lexbor before 2.7.0 allows remote attackers to crash applications that process crafted HTML fragments. When the fragment parser receives ns = UNDEF, it creates a comment with the unknown-element constructor, then unsafely casts the comment and writes its data into element fields, corrupting qualified_name. Exploitation requires an application to pass attacker-controlled HTML into fragment parsing; the corrupted field is later treated as a pointer and dereferenced near the zero page.
The record
- CVE
- CVE-2026-29079
- Published
- Mar 13, 2026
- Updated
- Mar 13, 2026
- Vendor
- Lexbor
- Product
- Lexbor
- Classifications
- CWE-843, T1499
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 13, 2026CVE publishedPublication date reported by the CVE source.
- Mar 13, 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?
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- Affected versionversion=< 2.7.0
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What is affected?
Published CVSS scores
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Attacks
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Technologies
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Your stack
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