CVE-2026-29079 Type Confusion in Lexbor Fragment Parser
A type confusion flaw in the Lexbor HTML fragment parser allows attackers to corrupt memory and potentially execute arbitrary code or cause a crash.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-29079?
CVE-2026-29079 is a high-severity memory corruption vulnerability in lexbor, published on 13 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-843
Which versions are affected by CVE-2026-29079?
It affects 1 product.
Products include Lexbor Lexbor.
How do I fix CVE-2026-29079?
Upgrade to a fixed version.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-29079 being exploited?
There is no known exploitation of CVE-2026-29079 in the wild and no public exploit code.
Other vulnerabilities in lexbor
Sources
Also known as DEBIAN-CVE-2026-29079, GHSA-mrpr-v36q-2vp8, UBUNTU-CVE-2026-29079.