FirebirdSQL Firebird up to 3.0.13/4.0.6/5.0.3 ENGINE Name path traversal

Summaryinfo

A vulnerability classified as critical has been found in FirebirdSQL Firebird up to 3.0.13/4.0.6/5.0.3. Affected by this vulnerability is an unknown functionality of the component ENGINE Name Handler. This manipulation causes path traversal. This vulnerability is registered as CVE-2026-40342. Remote exploitation of the attack is possible. No exploit is available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability has been found in FirebirdSQL Firebird up to 3.0.13/4.0.6/5.0.3 and classified as critical. Affected by this vulnerability is some unknown processing of the component ENGINE Name Handler. The manipulation with an unknown input leads to a path traversal vulnerability. The CWE definition for the vulnerability is CWE-22. The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-40342 since 04/11/2026. The exploitation appears to be easy. The attack can be launched remotely. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1006 for this issue.

The vulnerability scanner Nessus provides a plugin with the ID 307396 (Linux Distros Unpatched Vulnerability : CVE-2026-40342), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 3.0.14, 4.0.7 or 5.0.4 eliminates this vulnerability. The upgrade is hosted for download at github.com.

The vulnerability is also documented in the vulnerability database at Tenable (307396). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Database Administration Software

Vendor

• FirebirdSQL

Name

• Firebird

Version

• 3.0.0
• 3.0.1
• 3.0.2
• 3.0.3
• 3.0.4
• 3.0.5
• 3.0.6
• 3.0.7
• 3.0.8
• 3.0.9
• 3.0.10
• 3.0.11
• 3.0.12
• 3.0.13
• 4.0.0
• 4.0.1
• 4.0.2
• 4.0.3
• 4.0.4
• 4.0.5
• 4.0.6
• 5.0.0
• 5.0.1
• 5.0.2
• 5.0.3

License

• open-source

Website

• Product: https://github.com/FirebirdSQL/firebird/

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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