CVE-2026-11799 UXSS in Focus for iOS / Klar Webkit navigation
An attacker can execute arbitrary scripts in the context of the Focus or Klar iOS browser, potentially compromising user sessions and data.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-11799?
CVE-2026-11799 is a high-severity cross-site scripting vulnerability in Mozilla Focus for iOS, published on 9 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
UXSS in Focus for iOS / Klar Webkit navigation. This vulnerability was fixed in Focus for iOS 151.3.1 and Klar for iOS 151.3.1.
Weakness: CWE-79
Which versions are affected by CVE-2026-11799?
It affects 2 products.
Products include Mozilla Focus, Mozilla Klar.
How do I fix CVE-2026-11799?
No fix has been published for CVE-2026-11799 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-11799 being exploited?
There is no known exploitation of CVE-2026-11799 in the wild and no public exploit code.
Sources
Also known as GHSA-2j9g-whc6-7j55.