CVE-2026-40342

Firebird: Path Traversal + Arbitrary File Write Leads to Remote Code Execution

State: Published
Severity: 10.0 Critical
Published: Apr 17, 2026
Updated: Apr 22, 2026
Reserved: Apr 10, 2026

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.

Scores

CVSS	Score	Vector	Source
3.1	10.0 Critical	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H	GitHub_M

Weaknesses

CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CWE-427 Uncontrolled Search Path Element
CWE-73 External Control of File Name or Path
CWE-94 Improper Control of Generation of Code ('Code Injection')

Affected Products

Product	Versions
firebirdFirebirdSQL	< 3.0.14Affected >= 4.0.0, < 4.0.7Affected >= 5.0.0, < 5.0.4Affected

References

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