Widely used browser (Mozilla Firefox) vulnerability enabling remote code execution; high-impact on enterprise endpoints and user systems, requires broad IT action.
CVE-2026-100772
Use-after-free in Firefox DOM enabling potential remote code execution via crafted web content.
Is CVE-2026-100772 being exploited?
Not confirmed. CVE-2026-100772 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-2026-100772?
CVE-2026-100772 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-2026-100772?
Yes. A fix has been recorded for CVE-2026-100772. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-100772 affect?
CVE-2026-100772 affects Mozilla Firefox < 157, Firefox ESR < 153.4, Firefox ESR < 140.17. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-100772?
Update to Firefox 157 or ESR 153.4/140.17 immediately; restrict untrusted web content.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote arbitrary code execution via crafted web content, allowing system compromise, data access, or malware execution as the user.
Immediate action required