LadybirdBrowser Ladybird WebAssembly WebAssemblyModule.cpp expired pointer dereference

Summaryinfo

A vulnerability identified as problematic has been detected in LadybirdBrowser Ladybird. This affects an unknown part of the file WebAssemblyModule.cpp of the component WebAssembly Module. This manipulation causes expired pointer dereference. This vulnerability is registered as CVE-2026-58592. Remote exploitation of the attack is possible. Furthermore, an exploit is available.

Detailsinfo

A vulnerability was found in LadybirdBrowser Ladybird (affected version not known). It has been declared as problematic. Affected by this vulnerability is some unknown functionality of the file WebAssemblyModule.cpp of the component WebAssembly Module. The manipulation with an unknown input leads to a expired pointer dereference vulnerability. The CWE definition for the vulnerability is CWE-825. The product dereferences a pointer that contains a location for memory that was previously valid, but is no longer valid. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

Ladybird 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.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-58592 since 07/01/2026. The exploitation appears to be difficult. The attack can be launched remotely. The exploitation doesn't need any form of authentication. It demands that the victim is doing some kind of user interaction. Technical details and also a public exploit are known.

It is possible to download the exploit at github.com. It is declared as proof-of-concept.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Vendor

• LadybirdBrowser

Name

• Ladybird

CPE 2.3info

• 🔒

CPE 2.2info

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