FirebirdSQL Firebird up to 3.0.13/4.0.6/5.0.3 grow size memory corruption

Summaryinfo

A vulnerability was found in FirebirdSQL Firebird up to 3.0.13/4.0.6/5.0.3. It has been declared as critical. This issue affects the function grow. The manipulation of the argument size results in memory corruption. This vulnerability was named CVE-2026-27890. The attack may be performed from remote. There is no available exploit. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in FirebirdSQL Firebird up to 3.0.13/4.0.6/5.0.3. It has been classified as critical. Affected is the function grow. The manipulation of the argument size with an unknown input leads to a memory corruption vulnerability. CWE is classifying the issue as CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is available at github.com. This vulnerability is traded as CVE-2026-27890 since 02/24/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Technical details are known, but there is no available exploit.

Upgrading to version 3.0.14, 4.0.7 or 5.0.4 eliminates this vulnerability. The upgrade is hosted for download at github.com.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

• Database Administration Software

Vendor

• FirebirdSQL

Name

• Firebird

Version

• 3.0.0
• 3.0.1
• 3.0.2
• 3.0.3
• 3.0.4
• 3.0.5
• 3.0.6
• 3.0.7
• 3.0.8
• 3.0.9
• 3.0.10
• 3.0.11
• 3.0.12
• 3.0.13
• 4.0.0
• 4.0.1
• 4.0.2
• 4.0.3
• 4.0.4
• 4.0.5
• 4.0.6
• 5.0.0
• 5.0.1
• 5.0.2
• 5.0.3

License

• open-source

Website

• Product: https://github.com/FirebirdSQL/firebird/

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