# CVE-2026-40342

> Vulnerability · severity: **CRITICAL** (CVSS 9.9).

## 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.

## Key facts

- **CVE ID:** CVE-2026-40342
- **Published:** 2026-04-17
- **CVSS severity:** CRITICAL
- **CVSS base score:** 9.9
- **CWE codes:** CWE-22, CWE-73, CWE-94, CWE-427

## Affected products

- `firebirdsql:firebird`

## Primary sources

- NIST NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-40342

## Citation

> AI Analytics. CVE-2026-40342. Retrieved 2026-07-03 from https://api.ai-analytics.org/cve/CVE-2026-40342. Derived from NIST NVD. Licensed CC0.

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