Affects widely used browser apps; high risk of RCE; broad endpoint exposure.
CVE-2026-2807
Memory safety bugs in Firefox 147 and Thunderbird 147 may allow arbitrary code execution.
Is CVE-2026-2807 being exploited?
Not confirmed. CVE-2026-2807 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 0.24% probability of exploitation in the next 30 days.
How severe is CVE-2026-2807?
CVE-2026-2807 is rated Critical with a CVSS score of 9.8. 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-2026-2807?
Yes. A fix has been recorded for CVE-2026-2807. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-2807 affect?
CVE-2026-2807 affects Firefox < 148, Thunderbird < 148. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-2807?
Upgrade to 148+ (Firefox/Thunderbird).
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote code execution via memory corruption in Firefox/Thunderbird before 148; attacker could take control of the host.
Patch when possible