CVE-2026-84117
Privilege escalation in Firefox for Android allowing local elevation of privileges.
Is CVE-2026-84117 being exploited?
Not confirmed. CVE-2026-84117 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.23% probability of exploitation in the next 30 days.
How severe is CVE-2026-84117?
CVE-2026-84117 is rated High with a CVSS score of 8.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-84117?
Yes. A fix has been recorded for CVE-2026-84117. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-84117 affect?
CVE-2026-84117 affects Mozilla Firefox for Android < 155, Android devices running vulnerable Firefox builds. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-84117?
Update Firefox for Android to version 155 or later immediately.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Local privilege escalation in Firefox for Android enabling sandbox escape, elevated privileges, access to user data and higher-privileged actions.
Patch when possible