CVE-2026-74989
Memory-corruption bugs in Thunderbird 153 enabling potential code execution.
Is CVE-2026-74989 being exploited?
Not confirmed. CVE-2026-74989 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 0.33% probability of exploitation in the next 30 days.
How severe is CVE-2026-74989?
CVE-2026-74989 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-2026-74989?
Yes. A fix has been recorded for CVE-2026-74989. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-74989 affect?
CVE-2026-74989 affects Mozilla Thunderbird <= 153 (fixed in 154). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-74989?
Upgrade to Thunderbird 154 immediately.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Memory corruption could allow remote code execution via crafted email, attachment or web content, enabling full system compromise.
Immediate action required