Description
An attacker with control over a content process could potentially leverage the privileged UITour actor to leak sensitive information or escalate privileges. This vulnerability was fixed in Firefox 138 and Thunderbird 138.
Affected products
mozilla: firefox; mozilla: thunderbird
References3
- www.mozilla.org/security/advisories/mfsa2025-28/ Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2025-31/ Vendor Advisory
- bugzilla.mozilla.org/show_bug.cgi?id=1915280 Permissions Required
Metrics
- CVSS 3.1
-
7.1
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N - EPSS — exploit probability
- 0% percentile: 23 · as of 7 November 2026
- CWE
- CWE-269
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.