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CVE-2026-103418

Firefox for iOS: Universal XSS via the HTML language attribute in Translation Services

Mozilla Firefox for iOSApplications & CMS
Open in ThreatlineRecord JSON
CVSS
8.8High
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.30%Chance of exploitation activity in the next 30 days, higher than 21% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed inNone listedNo source names a fixed version. Check the vendor advisory below
Published13 Oct 2026Updated 14 Oct 2026CVE List

What fixes it

No source in this snapshot names a fixed version. The vendor advisories under References are the place to check.

Description

Firefox for iOS directly interpolated the page’s HTML language attribute into translation JavaScript, allowing attacker-controlled markup to execute code in Firefox’s privileged content world and bypass the page’s Content Security Policy. This vulnerability was fixed in Firefox for iOS 157.1.

Text from CVE List

Affected versions 1

  • Firefox for iOSunaffected: 157.1CVE List

References 2