CVE-2026-40342: Firebird is an open-source relational database management system. In versions prior to 5.0.4, 4.0.7 and 3.0.14, the…
CVE-2026-40342 · Severity: critical · CVSS 9.9 · Published 2026-04-17
Firebird is an open-source relational database management system. In versions prior to 5.0.4, 4.0.7 and 3.0.14, the external engine plugin loader concatenates a user-supplied engine name into a filesystem path without filtering path separators or .. components. An authenticated user with CREATE FUNCTION privileges can use a crafted ENGINE name to load an arbitrary shared library from anywhere on the filesystem via path traversal. The library's initialization code executes immediately during loading, before Firebird validates the module, achieving code execution as the server's OS account. This issue has been fixed in versions 5.0.4, 4.0.7 and 3.0.14.
No. Junglewise Threat Intelligence has no report of CVE-2026-40342 being exploited in the wild.
How severe is CVE-2026-40342?
Critical severity, with a CVSS score of 9.9, published 17 April 2026.
Which products and versions are affected?
Firebirdsql Firebird. The advisory does not name versions.
Is there a fix for CVE-2026-40342?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
Am I affected by CVE-2026-40342?
Check whether you run Firebirdsql Firebird. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.