CVE-2026-2634 Spoofed web content presented under trusted domains using scripted navigation on Firefox iOS

What is CVE-2026-2634?

CVE-2026-2634 is a critical vulnerability in Mozilla Firefox, published on 24 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Malicious scripts could cause desynchronization between the address bar and web content before a response is received in Firefox iOS, allowing attacker-controlled pages to be presented under spoofed domains. This vulnerability was fixed in Firefox for iOS 147.4.

Weakness: CWE-451

Which versions are affected by CVE-2026-2634?

It affects 1 product.

Products include Mozilla Firefox.

How do I fix CVE-2026-2634?

No fix has been published for CVE-2026-2634 yet. Limit exposure of the affected software until one is available.

Is CVE-2026-2634 being exploited?

There is no known exploitation of CVE-2026-2634 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-gwgg-r543-4wvw, UBUNTU-CVE-2026-2634.