CVE-2026-119331
HighCVSS 7.1Exploitation Probability (EPSS)
Low risk8th percentile - higher than 8% of all known CVEs
Summary
In the Ladybird browser prior to commit c0d68bd, CSSStyleSheet.cssRules, insertRule(), and deleteRule() 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 rules and insert or delete rules in the victim stylesheet, bypassing the Same-Origin Policy.
Risk Assessment
An attacker can expose selectors, generated content, and other sensitive rule text, and alter the visibility or layout of the victim page. The issue does not lead to memory corruption or code execution.
Recommendation
Update Ladybird to a version containing commit c0d68bddf3e3616e5173835f0f4c155ee9700d91 or later. Until then, limit browsing to trusted sites.
Other vulnerabilities in Ladybird
See all- CVE-2026-119332High
In the Ladybird browser prior to commit 209579c, FinalizationRegistry::cleanup() removed a dead record, retained an iterator to the next record, and then invoked attacker-controlled JavaScript through the cleanup callback. If that callback called unregister() for the next record, the retained iterator referenced a freed node, and the next iteration read its fields after free.
- CVE-2026-58592High
Ladybird before commit 2f9dc7e contains a dangling-reference memory-safety flaw in its WebAssembly ESM-integration module loader. When a JavaScript function is imported into a WebAssembly module via the ESM path, WebAssemblyModule.cpp passes a stack-local Wasm::FunctionType by reference to create_host_function, whose host callback captures and later reads that reference; once the ESM link-loop iteration ends the FunctionType is destroyed, leaving the callback with a dangling reference. Stale result-type data lets the host callback return an empty result vector for a statically non-empty result, so the destination register retains an attacker-influenced value that is then consumed by the WASM-GC array.set handler, which bit-casts the reference low bits to an ArrayInstance pointer after only a null check, yielding an arbitrary write.
Original NVD description (English source)
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.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS