Reference page — cumulative record through Sunday, October 4, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
CVE-2026-58592
LadybirdBrowser Ladybird — Ladybird - Web-Reachable Code Execution via Dangling FunctionType Reference in WebAssembly ESM Integration
AV AC AT PR UI VC VI VA CVSS EPSS %ile KEV
N H P N A H H H 8.9 .0055 44.0 —
AFFECTED
Product Versions Fixed
Ladybird unspecified —
TIMELINE
Jul 1 Reserved by VulnCheck
Jul 1 Published (CNA: VulnCheck)
Sep 11 EXPLOIT PUBLISHED — CVE-2026-58592 (LadybirdBrowser Ladybird). Public exploit reference added.
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.
Lifecycle
Complete event history — 3 events, chronological
| Date | Event | Detail |
|---|
| July 1, 2026 | Reserved | Reserved by VulnCheck |
| July 1, 2026 | Published | Published (CNA: VulnCheck) |
| September 11, 2026 | EXPLOIT PUBLISHED | EXPLOIT PUBLISHED — CVE-2026-58592 (LadybirdBrowser Ladybird). Public exploit reference added. |
Affected
Affected products and packages — 1 row
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
|---|
| LadybirdBrowser | Ladybird | — | — | — |
About this page
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-58592 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Sunday, October 4, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.
