CVE-2026-119331

What it is

Ladybird is a truly independent web browser. Prior to the c0d68bddf3e3616e5173835f0f4c155ee9700d91 commit, CSSStyleSheet.cssRules, insertRule(), and deleteRule() in Libraries/LibWeb/CSS/CSSStyleSheet.cpp did not enforce the stylesheet origin-clean flag with the required SecurityError, even though cross-origin imported stylesheets were correctly marked non-origin-clean. A malicious page could read parsed rules from a stylesheet loaded without CORS and could insert or delete rules in the victim stylesheet, bypassing the Same-Origin Policy. Reading could expose selectors, generated content, feature markers, or other sensitive rule text, while mutation could alter page visibility or layout. The issue does not provide memory corruption, code execution, or persistence after the attacker page closes. This vulnerability is fixed by commit c0d68bddf3e3616e5173835f0f4c155ee9700d91.

At a glance

Exploitability

Can be exploited over the network without logging in, but needs a user to act. High risk of data exposure.

Exploit odds

0.2% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-10-30 20:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-11-02 19:35 UTC Last updatedMost recent change to the record

Details

Published

2026-10-30 20:17 UTC

Last modified

2026-11-02 19:35 UTC

Exploit probability

0.2% · EPSS, next 30 days

Weakness

CWE-200 · Information exposure

Record status

Deferred

Attack profile CVSS 3.1 · 7.1

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

Low

Availability

None