CVE-2026-58592
HighCVSS 8.3Exploitation Probability (EPSS)
Low risk46th percentile - higher than 46% of all known CVEs
Summary
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.
Risk Assessment
A web page can chain this into code execution in the WebContent process. The risk is critical because the vulnerability is reachable from HTML content without any instrumentation or source modification.
Recommendation
Upgrade Ladybird to commit 2f9dc7e or later. Until patched, consider restricting execution of WebAssembly content from untrusted pages.
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-2026-119331High
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.
Original NVD description (English source)
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 (the normal instantiate path uses a long-lived reference and is not affected). 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. A web page can chain this into code execution in the WebContent process. Verified reachable from HTML content without any instrumentation or source modification.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS