CVE-2026-27890
Fixed in a distro release EPSS <1%CVSS 8.2
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.
Products: firebirdsql firebird
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| Debian 12 | firebird3.0 | no fix |
| Debian 13 | firebird3.0 | no fix |
| Debian 13 | firebird4.0 | no fix |
| Debian 14 | firebird3.0 | 3.0.14.ds7-1 |
| Debian 14 | firebird4.0 | 4.0.7.3271.ds6-1 |
| Ubuntu 18.04 LTS | firebird3.0 | no fix |
| Ubuntu 20.04 LTS | firebird3.0 | no fix |
| Ubuntu 22.04 LTS | firebird3.0 | no fix |
| Ubuntu 24.04 LTS | firebird3.0 | no fix |
| Ubuntu 25.10 | firebird3.0 | no fix |
| Ubuntu 25.10 | firebird4.0 | no fix |
| Ubuntu 26.04 LTS | firebird3.0 | no fix |
| Ubuntu 26.04 LTS | firebird4.0 | no fix |
| Ubuntu 26.10 | firebird3.0 | no fix |
| Ubuntu 26.10 | firebird4.0 | no fix |