CVE-2026-13356 Interrupted navigation could allow address bar origin spoofing in Firefox for iOS

What is CVE-2026-13356?

CVE-2026-13356 is a medium-severity vulnerability in Mozilla Firefox, published on 6 Jul 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

A malicious webpage could interrupt a pending navigation by enqueuing a synchronous JavaScript dialog, causing the browser UI to display the destination origin in the address bar while continuing to render attacker-controlled content. This vulnerability was fixed in Firefox for iOS 152.3.

Weakness: CWE-451

Which versions are affected by CVE-2026-13356?

It affects 1 product.

Products include Mozilla Firefox.

How do I fix CVE-2026-13356?

No fix has been published for CVE-2026-13356 yet. Limit exposure of the affected software until one is available.

Is CVE-2026-13356 being exploited?

There is no known exploitation of CVE-2026-13356 in the wild and no public exploit code.

Other vulnerabilities in Mozilla Firefox

• CVE-2019-11708 Mozilla Firefox and Thunderbird Sandbox Escape Exploited Critical 10.0
• CVE-2010-3765 Mozilla Multiple Products Remote Code Execution Exploited Critical 9.8
• CVE-2022-26486 Mozilla Firefox Use-After-Free Exploited Critical 9.6
• CVE-2022-26485 Mozilla Firefox Use-After-Free Exploited High 8.8
• CVE-2019-11707 Mozilla Firefox and Thunderbird Type Confusion Exploited High 8.8

All Mozilla Firefox vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-66fv-p34j-fwgr.