Skip to main content
Meet us at Black Hat USA 2026— Las Vegas, August 1–6Book a Meeting
Mallory
Unrated

Use-after-free in Apple Web Extensions

IdentifiersCVE-2026-43704CWE-416

CVE-2026-43704 is a use-after-free vulnerability in Apple Web Extensions. Apple states that the issue was addressed through improved memory management. Successful triggering of the flaw by a malicious web extension can lead to an unexpected process crash. The issue affects Safari 26.5.2 prior to patching, iOS 26.5.2 prior to patching, iPadOS 26.5.2 prior to patching, and macOS Tahoe 26.5.2 prior to patching.

Share:
For your environment

Are you exposed to this one?

Mallory correlates every CVE against your assets, your vendors, and active adversary campaigns. Know which vulnerabilities matter for you, not just which ones are loud.

ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

The documented impact is denial of service at the affected process level: a malicious web extension may trigger the use-after-free condition and cause an unexpected process crash. Based on the provided content, there is no specific evidence that Apple reported code execution, privilege escalation, or data disclosure for this CVE.

Mitigation

If you can’t patch tonight, do this now.

If immediate patching is not possible, reduce exposure by disabling or tightly restricting installation and use of untrusted or unnecessary web extensions, enforcing extension allowlisting where available, and limiting users' ability to install third-party extensions. These are compensating controls only; the authoritative fix is to install Apple's security updates.

Remediation

Patch, then assume compromise.

Apply Apple's fixes by upgrading to Safari 26.5.2, iOS 26.5.2, iPadOS 26.5.2, and macOS Tahoe 26.5.2, or later versions that include the patch. Apple indicates the vulnerability was remediated with improved memory management in the affected component.
PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

What this page doesn’t show

The version that knows your environment.

This page is what’s public. Mallory adds the parts that aren’t: which of your assets are affected, which adversaries are exploiting it right now, which detections to deploy, and what to do tonight.
Exposure mapping

Query your assets running an affected version, and investigate the blast radius.

Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity

Community discussion across Reddit, Mastodon, and other social sources.