CVE-2026-8970
Privilege escalation in Mozilla Firefox/Thunderbird Security component.
Is CVE-2026-8970 being exploited?
Not confirmed. CVE-2026-8970 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 0.31% probability of exploitation in the next 30 days.
How severe is CVE-2026-8970?
CVE-2026-8970 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-2026-8970?
Yes. A fix has been recorded for CVE-2026-8970. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-8970 affect?
CVE-2026-8970 affects Mozilla Firefox, Mozilla Firefox ESR, Mozilla Thunderbird, Mozilla Thunderbird ESR. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-8970?
Update to latest Firefox/Thunderbird builds
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Local privilege escalation via Firefox/Thunderbird Security module; attacker gains higher OS/app privileges after exploit.
Patch when possible