CVE-2026-27890
CWE-119Published: April 17, 2026· Updated: Apr 20, 2026
Official Description
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 order. If segments arrive out of order, the Array class's grow() method computes a negative size value, causing a SIGSEGV crash. An unauthenticated attacker who knows only the server's IP and port can exploit this to crash the server. This issue has been fixed in versions 5.0.4, 4.0.7 and 3.0.14.
Technical Analysis
CVE-2026-27890 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
A successful exploit results in availability disruption (denial of service), with a CVSS base score of 8.2.
From a weakness classification perspective (CWE-119): Buffer overflow vulnerabilities can lead to arbitrary code execution or denial of service by corrupting adjacent memory.
CVSS v3.1 Vector Breakdown
Exploit & PoC Resources
All References (4)
Quick Facts
Related CVEs (CWE-119)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-27890 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts