VulnerabilityAnalyzed

CVE-2026-29079

Prior to 2.7.0, a type‑confusion vulnerability exists in Lexbor’s HTML fragment parser.

HIGH 8.2EPSS 0.26%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.26%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

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.

CVSS 4.0: 8.2 HIGHCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS: 0.26% probability · 18th percentile
CISA KEV: Not listed
Weakness: CWE-843
Affected: lexbor/lexbor
Source: security-advisories@github.com

References

https://github.com/lexbor/lexbor/security/advisories/GHSA-mrpr-v36q-2vp8Vendor Advisory

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.