# CVE-2026-58592

## Summary

- **CVE ID:** CVE-2026-58592
- **Severity:** HIGH
- **CVSS Score:** 8.9 (CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H)
- **CWE:** CWE-825, CWE-843, CWE-787
- **Published:** Jul 1, 2026
- **Last Modified:** Jul 2, 2026

## Description

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.

## Affected Products

- LadybirdBrowser — Ladybird (0)

## References

- [CNA](https://github.com/bikini/exploitarium/tree/main/ladybird-wasm-esm-host-function-rce-poc)
- [CNA](https://github.com/LadybirdBrowser/ladybird/blob/master/Libraries/LibWeb/WebAssembly/WebAssemblyModule.cpp)
- [CNA](https://www.vulncheck.com/advisories/ladybird-web-reachable-code-execution-via-dangling-functiontype-reference-in-webassembly-esm-integration)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.53%
- **EPSS Percentile:** 43.0

---
_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-09._