Critical severity · published Apr 17, 2026
CVE-2026-40342
Firebird: Path Traversal + Arbitrary File Write Leads to Remote Code Execution
9.9
CVSS
0.7%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.7% · higher than 53% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FI
firebird · FirebirdSQL
< 3.0.14; >= 4.0.0, < 4.0.7; >= 5.0.0, < 5.0.4 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-40342
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-40342
Release Notes
https://github.com/FirebirdSQL/firebird/releases/tag/v3.0.14
Release Notes
https://github.com/FirebirdSQL/firebird/releases/tag/v4.0.7
Release Notes
https://github.com/FirebirdSQL/firebird/releases/tag/v5.0.4
Exploit
https://github.com/FirebirdSQL/firebird/security/advisories/GHSA-7pxc-h3rv-r257
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