Vulnerability in Lexbor

CVE-2026-29079

Lexbor is a web browser engine library. Prior to 2.7.0, a type‑confusion vulnerability exists in Lexbor’s HTML fragment parser. When ns = UNDEF, a comment is created using the “unknown element” constructor. The comment’s data are written into the element’s fields via an unsafe cast, corrupting the qualified_name field. That corrupted value is later used as a pointer and dereferenced near the zero page. This vulnerability is fixed in 2.7.0.

EPSS: 0.003 (18.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-29079?
CVE-2026-29079 is a high-severity vulnerability in Lexbor, classified under Access of Resource Using Incompatible Type (Type Confusion). CVSS score: 7.5/10. Published 2026-03-13.
How severe is CVE-2026-29079?
High severity. CVSS v3 base score is 7.5 out of 10.