Affects widely deployed Mozilla products (Firefox/Thunderbird). Privilege escalation via browser graphics component can lead to sandbox escape and host compromise, warranting broad org notice.
CVE-2026-100764
WebGPU sandbox escape causing privilege escalation in Firefox/Thunderbird
Is CVE-2026-100764 being exploited?
Not confirmed. CVE-2026-100764 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 0.25% probability of exploitation in the next 30 days.
How severe is CVE-2026-100764?
CVE-2026-100764 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-2026-100764?
Yes. A fix has been recorded for CVE-2026-100764. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-100764 affect?
CVE-2026-100764 affects Mozilla Firefox < 157, Mozilla Thunderbird < 157. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-100764?
Update to Firefox/Thunderbird 157+ immediately
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Crafted WebGPU content can exploit boundary errors to escape the browser sandbox and escalate privileges, allowing code execution or host compromise.
Immediate action required