CVE-2026-74988
Memory corruption in Thunderbird 153 enabling remote code execution.
Is CVE-2026-74988 being exploited?
Not confirmed. CVE-2026-74988 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 0.35% probability of exploitation in the next 30 days.
How severe is CVE-2026-74988?
CVE-2026-74988 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-2026-74988?
Yes. A fix has been recorded for CVE-2026-74988. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-74988 affect?
CVE-2026-74988 affects Thunderbird 153, Thunderbird ESR 153.0. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-74988?
Upgrade to Thunderbird 153.1 or 154 immediately; apply vendor updates.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote code execution via memory corruption from crafted email/content; attacker can execute code as the user.
Immediate action required