CVE-2026-27890
Received
Received - Intake
Segmentation Fault in Firebird Authentication via Out-of-Order Data
Publication date: 2026-04-17
Last updated on: 2026-04-24
Assigner: GitHub, Inc.
Description
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.
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| firebirdsql | firebird | to 3.0.14 (exc) |
| firebirdsql | firebird | From 4.0.0 (inc) to 4.0.7 (exc) |
| firebirdsql | firebird | From 5.0.0 (inc) to 5.0.4 (exc) |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-119 | The 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-787 | The product writes data past the end, or before the beginning, of the intended buffer. |
