CVE-2026-58592Public exploitNetwork attack vector

Code execution via dangling WebAssembly function type

Published Jul 1, 2026 · Updated Jul 1, 2026

Memory corruption in Ladybird version 0 allows remote attackers to execute code in the WebContent process through a crafted web page. The ESM loader passes a stack-local Wasm::FunctionType by reference into a host callback, which later reads it after destruction and leaves a stale result register. Visiting attacker-controlled HTML is sufficient; WASM-GC array.set treats the register's low bits as an ArrayInstance pointer after only a null check, enabling an arbitrary write and native code execution inside the renderer.

CVSS severity8.9
High
EPSS probability0.55%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory corruption in Ladybird version 0 allows remote attackers to execute code in the WebContent process through a crafted web page. The ESM loader passes a stack-local Wasm::FunctionType by reference into a host callback, which later reads it after destruction and leaves a stale result register. Visiting attacker-controlled HTML is sufficient; WASM-GC array.set treats the register's low bits as an ArrayInstance pointer after only a null check, enabling an arbitrary write and native code execution inside the renderer.

The record

CVE
CVE-2026-58592
Published
Jul 1, 2026
Updated
Jul 1, 2026
Vendor
Ladybird Browser Initiative
Product
Ladybird
Classifications
CWE-787, CWE-843, CWE-825, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 1, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 1, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Ladybird Browser Initiative · Ladybirdversion=0

Published CVSS scores

8.9VulnCheckCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
8.3VulnCheckCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-787Out-of-bounds Write
CWE-843Access of Resource Using Incompatible Type ('Type Confusion')
CWE-825Expired Pointer Dereference
T1203Exploitation for Client Execution

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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