CVE-2026-28224

Received Received - Intake

Null Pointer Dereference in Firebird Server Causes Denial of Service

Publication date: 2026-04-17

Last updated on: 2026-04-24

Assigner: GitHub, Inc.

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 the server receives an op_crypt_key_callback packet without prior authentication, the port_server_crypt_callback handler is not initialized, resulting in a null pointer dereference and server 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

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Meta Information

Published

2026-04-17

Last Modified

2026-04-24

Generated

2026-07-06

AI Q&A

2026-04-18

EPSS Evaluated

2026-07-05

NVD

CVE-2026-28224

EUVD

EUVD-2026-23468

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-476	The product dereferences a pointer that it expects to be valid but is NULL.

Attack-Flow Graph

Compliance Impact

The vulnerability allows an unauthenticated attacker to crash the Firebird server by sending a specially crafted packet, resulting in a denial of service. However, there is no information provided about any impact on data confidentiality or integrity, nor about any direct effects on compliance with standards such as GDPR or HIPAA.

Since the vulnerability causes a server crash without data breach or unauthorized data access, its impact on compliance with regulations that focus on data protection and privacy is likely limited to availability concerns.

Executive Summary

This vulnerability exists in Firebird, an open-source relational database management system, in versions prior to 5.0.4, 4.0.7, and 3.0.14. When the server receives an op_crypt_key_callback packet without prior authentication, the port_server_crypt_callback handler is not initialized. This leads to a null pointer dereference, causing the server to crash.

An attacker who is unauthenticated and only knows the server's IP address and port can exploit this vulnerability to crash the server.

Impact Analysis

This vulnerability can be exploited by an unauthenticated attacker to cause a denial of service by crashing the Firebird server. This can lead to service disruption, affecting availability and potentially causing downtime for applications relying on the database.

Mitigation Strategies

To mitigate this vulnerability, you should upgrade your Firebird server to version 5.0.4, 4.0.7, or 3.0.14 or later, as these versions contain the fix for the issue.

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