CVE-2026-27890: firebirdsql firebird

Vulnerability summary

CVE-2026-27890 is a high (CVSS 8.2) vulnerability in firebirdsql firebird. EPSS estimates a 0.72% chance of exploitation in the next 30 days, higher than 53.2% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 17-04-2026
   PublishedVulnerability first disclosed.
2. 17-04-2026
   Last modifiedVulnerability information updated.

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.

• CWE-119Improper Restriction of Operations within the Bounds of a Memory BufferThe product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.
• CWE-787Out-of-bounds WriteThe product writes data past the end, or before the beginning, of the intended buffer.