Affects widely used Mozilla products (Firefox/Thunderbird); privilege escalation on endpoints can lead to compromised workstations and lateral movement, warranting broad IT notice.
CVE-2026-100782
Privilege escalation in Firefox/Thunderbird graphics component (bounds error).
Is CVE-2026-100782 being exploited?
Not confirmed. CVE-2026-100782 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.
How severe is CVE-2026-100782?
CVE-2026-100782 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-2026-100782?
Yes. A fix has been recorded for CVE-2026-100782. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-100782 affect?
CVE-2026-100782 affects Mozilla Firefox, Firefox ESR, Mozilla Thunderbird. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-100782?
Apply Mozilla security updates immediately to the fixed versions.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Graphics component boundary error allows local privilege escalation, potentially enabling elevated code execution or system compromise.
Immediate action required