Vulnerability · Published Oct 13, 2026 · Assigned by mozilla
CVE-2026-103418Universal XSS via the HTML language attribute in Translation Services
High 8.8
In plain English
A high-severity cross-site scripting in Firefox for iOS from Mozilla. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 23% of all known vulnerabilities).
Severity (CVSS 3.1)8.8High
Exploit odds (30 days)0.3%top 77.0% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official 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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Firefox for iOS | see references |
Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H