Buffer overflow in Firebirdsql Firebird
CVE-2026-27890
Firebird is an open-source relational database management system. In versions prior to 5.0.4, 4.0.7 and 3.0.14, when processing CNCT_specific_data segments during authentication, the server assumes segments arrive in strictly ascending ord…
Vulnerability class: Buffer Overflow
EPSS: 0.006 (69.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H.
Affected products
- Firebirdsql Firebird — versions >= 3.0.0, < 3.0.14, >= 4.0.0, < 4.0.7, >= 5.0.0, < 5.0.4
Weakness classification (CWE)
References
- https://github.com/FirebirdSQL/firebird/security/advisories/GHSA-6crx-4g37-7j49 (x_refsource_CONFIRM)
- https://github.com/FirebirdSQL/firebird/releases/tag/v3.0.14 (x_refsource_MISC)
- https://github.com/FirebirdSQL/firebird/releases/tag/v4.0.7 (x_refsource_MISC)
- https://github.com/FirebirdSQL/firebird/releases/tag/v5.0.4 (x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-27890?
- CVE-2026-27890 is a high-severity vulnerability in Firebirdsql Firebird, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 8.2/10. Published 2026-04-17.
- How severe is CVE-2026-27890?
- High severity. CVSS v3 base score is 8.2 out of 10.