CVE-2026-8952
Privilege escalation in Firefox/Thunderbird update component.
Is CVE-2026-8952 being exploited?
Not confirmed. CVE-2026-8952 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 0.37% probability of exploitation in the next 30 days.
How severe is CVE-2026-8952?
CVE-2026-8952 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-2026-8952?
Yes. A fix has been recorded for CVE-2026-8952. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-8952 affect?
CVE-2026-8952 affects Firefox (Desktop), Thunderbird (Desktop). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-8952?
Update to Firefox/Thunderbird 151+
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Local privilege escalation via the update component; may grant elevated rights on the host.
Patch when possible