CVE-2026-40342
Privilege escalation in Firebird via engine loader path traversal
Is CVE-2026-40342 being exploited?
Not confirmed. CVE-2026-40342 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 0.69% probability of exploitation in the next 30 days.
How severe is CVE-2026-40342?
CVE-2026-40342 is rated Critical with a CVSS score of 9.9. 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-2026-40342?
Yes. A fix has been recorded for CVE-2026-40342. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-40342 affect?
CVE-2026-40342 affects Firebird 5.x before 5.0.4, Firebird 4.x before 4.0.7, Firebird 3.x before 3.0.14. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-40342?
Upgrade to fixed versions: 5.0.4+, 4.0.7+, or 3.0.14+
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Authenticated user with CREATE FUNCTION can load a crafted library and execute code on the server OS.
Immediate action required
- affected< 3.0.14
- affected>= 4.0.0 and < 4.0.7
- affected>= 5.0.0 and < 5.0.4
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.