CVE-2026-74935
Privilege escalation in Firefox/Thunderbird DOM networking component.
Is CVE-2026-74935 being exploited?
Not confirmed. CVE-2026-74935 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-2026-74935?
CVE-2026-74935 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-2026-74935?
Yes. A fix has been recorded for CVE-2026-74935. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-74935 affect?
CVE-2026-74935 affects Mozilla Firefox < 154, Firefox ESR < 115.39, Firefox ESR < 140.14, Firefox ESR < 153.1, and 3 further products or versions. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-74935?
Update Firefox/Thunderbird to the listed patched versions immediately.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Crafted web content or message can escalate privileges from content to higher-privilege process, enabling access to local resources or potential code execution.
Immediate action required