CVE-2026-40342

Critical

Description

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.

SeverityCritical
CVSS9.9
Exploit probability—
ProductFirebird
PublishedApr 17, 2026
First seenApr 17, 2026

How to fix

Update
  • firebirdsql firebird3.0.14, 4.0.7, 5.0.4 or later

Affected products

ProductAffected versionsFixed in
firebirdsql firebirdv < 3.0.14, 4.0.0 ≤ v < 4.0.7, 5.0.0 ≤ v < 5.0.43.0.14, 4.0.7, 5.0.4

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