CVE-2026-58592: LadybirdBrowser Ladybird · Expired Pointer Dereference
Affects LadybirdBrowser LadybirdSource CVE Database V5
Not known to be exploited · CVSS 8.3 High.
Data as of 13 Nov 2026, 12:10 UTC
Thin evidence
One scorer or none| CNA (VulnCheck) | CVSS 3.1 | 8.3 |
|---|---|---|
| CNA (VulnCheck) | CVSS 4.0 | 8.9 |
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 46% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 1 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 13 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LadybirdBrowserLadybird | Affected
| Fixed in– |
AI-suggested
Until an official fix is available, users should exercise caution when browsing untrusted web content. No vendor-provided mitigation or temporary workaround information is currently available.
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.
References
- github.com/bikini/exploitarium/tree/main/ladybird-wasm-esm-host-function-rce-poc (opens in a new tab)
- github.com/LadybirdBrowser/ladybird/blob/master/Libraries/LibWeb/WebAssembly/WebAssemblyModule.cpp (opens in a new tab)
- vulncheck.com/advisories/ladybird-web-reachable-code-execution-via-dangling-functiontype-reference-in-webassembly-esm-integration (opens in a new tab)
- github.com/LadybirdBrowser/ladybird/issues/11569 (opens in a new tab)
- github.com/LadybirdBrowser/ladybird/pull/11606 (opens in a new tab)
- github.com/LadybirdBrowser/ladybird/commit/2f9dc7e9f35eed67dde3f9e8567d390dc4f0c665 (opens in a new tab)