{"id":"CVE-2026-58592","state":"PUBLISHED","title":"Ladybird - Web-Reachable Code Execution via Dangling FunctionType Reference in WebAssembly ESM Integration","description":"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.","publishedAt":"2026-07-01T19:27:22.629Z","updatedAt":"2026-09-11T14:41:04.811Z","severity":{"score":8.9,"label":"High","version":"4.0","vector":"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","source":"VulnCheck"},"assigner":"VulnCheck","products":["LadybirdBrowser Ladybird"],"affected":[{"vendor":"LadybirdBrowser","product":"Ladybird","defaultStatus":"affected","versions":[{"version":"0","status":"affected","lessThan":"2f9dc7e9f35eed67dde3f9e8567d390dc4f0c665","versionType":"git"}]}],"references":["https://github.com/bikini/exploitarium/tree/main/ladybird-wasm-esm-host-function-rce-poc","https://github.com/LadybirdBrowser/ladybird/issues/11569","https://github.com/LadybirdBrowser/ladybird/pull/11606","https://github.com/LadybirdBrowser/ladybird/commit/2f9dc7e9f35eed67dde3f9e8567d390dc4f0c665","https://www.vulncheck.com/advisories/ladybird-web-reachable-code-execution-via-dangling-functiontype-reference-in-webassembly-esm-integration"],"weaknesses":["CWE-825","CWE-843","CWE-787"],"ingestedAt":"2026-10-29T20:12:24.861Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/58xxx/CVE-2026-58592.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-58592","state":"PUBLISHED","datePublished":"2026-07-01T19:27:22.629Z","dateUpdated":"2026-09-11T14:41:04.811Z","assignerShortName":"VulnCheck","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateReserved":"2026-07-01T17:20:57.549Z"},"containers":{"cna":{"title":"Ladybird - Web-Reachable Code Execution via Dangling FunctionType Reference in WebAssembly ESM Integration","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"LadybirdBrowser","product":"Ladybird","defaultStatus":"affected","versions":[{"version":"0","status":"affected","lessThan":"2f9dc7e9f35eed67dde3f9e8567d390dc4f0c665","versionType":"git"}]}],"references":[{"url":"https://github.com/bikini/exploitarium/tree/main/ladybird-wasm-esm-host-function-rce-poc","name":"Proof of Concept","tags":["exploit"]},{"url":"https://github.com/LadybirdBrowser/ladybird/issues/11569","name":"GitHub Issue","tags":["issue-tracking"]},{"url":"https://github.com/LadybirdBrowser/ladybird/pull/11606","name":"Pull Request","tags":["issue-tracking"]},{"url":"https://github.com/LadybirdBrowser/ladybird/commit/2f9dc7e9f35eed67dde3f9e8567d390dc4f0c665","name":"Patch Commit","tags":["patch"]},{"url":"https://www.vulncheck.com/advisories/ladybird-web-reachable-code-execution-via-dangling-functiontype-reference-in-webassembly-esm-integration","name":"VulnCheck Advisory","tags":["third-party-advisory"]}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV3_1":{"attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"REQUIRED","scope":"CHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH","version":"3.1","baseSeverity":"HIGH","baseScore":8.3,"vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H"}},{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"HIGH","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"ACTIVE","vulnConfidentialityImpact":"HIGH","subConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","subIntegrityImpact":"HIGH","vulnAvailabilityImpact":"HIGH","subAvailabilityImpact":"HIGH","exploitMaturity":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED","version":"4.0","baseSeverity":"HIGH","baseScore":8.9,"vectorString":"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"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-825","lang":"en","description":"Expired Pointer Dereference","type":"CWE"},{"cweId":"CWE-843","lang":"en","description":"Access of Resource Using Incompatible Type ('Type Confusion')","type":"CWE"},{"cweId":"CWE-787","lang":"en","description":"Out-of-bounds Write","type":"CWE"}]}],"providerMetadata":{"shortName":"VulnCheck","orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateUpdated":"2026-09-11T14:41:04.811Z"},"datePublic":"2026-07-01T00:00:00.000Z","x_generator":{"engine":"vulncheck-endgame"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-02T15:27:43.547840Z","id":"CVE-2026-58592","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-07-02T15:55:07.091Z"}}]}}}