{"id":"CVE-2026-58592","title":"Ladybird before commit 2f9dc7e contains a dangling-reference memory-safety flaw in its WebAssembly ESM-integration module loader","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 pa…","severity":"high","cvss":8.3,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H","cwe":["CWE-787","CWE-825","CWE-843"],"vendor":"LadybirdBrowser","product":"Ladybird","affected":["Ladybird < 2f9dc7e9f35eed67dde3f9e8567d390dc4f0c665"],"published":"2026-07-01","updated":"2026-09-11","sourceUpdated":"2026-09-11T15:17:02.437","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-58592","references":[{"url":"https://github.com/LadybirdBrowser/ladybird/commit/2f9dc7e9f35eed67dde3f9e8567d390dc4f0c665","label":"disclosure@vulncheck.com"},{"url":"https://github.com/LadybirdBrowser/ladybird/issues/11569","label":"disclosure@vulncheck.com"},{"url":"https://github.com/LadybirdBrowser/ladybird/pull/11606","label":"disclosure@vulncheck.com"},{"url":"https://github.com/bikini/exploitarium/tree/main/ladybird-wasm-esm-host-function-rce-poc","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/ladybird-web-reachable-code-execution-via-dangling-functiontype-reference-in-webassembly-esm-integration","label":"disclosure@vulncheck.com"}],"tags":["nvd","cve.org","exploit-available"],"exploitAvailable":true,"ssvc":{"exploitation":"poc","automatable":"no","technicalImpact":"total","timestamp":"2026-07-02T15:27:43.547840Z"},"ingestedAt":"2026-09-14T15:23:05.964Z","epss":0.00549,"epssPercentile":0.44809,"slug":"CVE-2026-58592","body":"## Overview\n\nLadybird 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":58,"depthScoreParts":{"impact":45.7,"likelihood":0.1,"exploitation":12,"ransomware":0},"changes":[]}