CVE-2026-27890: CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer in FirebirdSQL firebird
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.
AI Analysis
Technical Summary
FirebirdSQL firebird versions before 5.0.4, 4.0.7, and 3.0.14 contain a memory handling flaw during authentication processing of CNCT_specific_data segments. The server incorrectly assumes segments arrive in ascending order; if they do not, the Array class's grow() method calculates a negative size, resulting in a segmentation fault crash. This allows an unauthenticated remote attacker to cause a denial of service by crashing the server. The vulnerability is tracked as CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) and CWE-787 (Out-of-bounds Write).
Potential Impact
An unauthenticated attacker who knows the server's IP address and port can remotely crash the FirebirdSQL server, causing a denial of service. There is no indication of confidentiality or integrity impact, but availability is severely affected. No known exploits in the wild have been reported at this time.
Mitigation Recommendations
This vulnerability is fixed in FirebirdSQL versions 5.0.4, 4.0.7, and 3.0.14. Users should upgrade to these or later versions to remediate the issue. Patch status is confirmed by the vendor's versioning information. No other mitigation or workaround is indicated.
CVE-2026-27890: CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer in FirebirdSQL firebird
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 v3.1
Score 8.2high
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
FirebirdSQL firebird versions before 5.0.4, 4.0.7, and 3.0.14 contain a memory handling flaw during authentication processing of CNCT_specific_data segments. The server incorrectly assumes segments arrive in ascending order; if they do not, the Array class's grow() method calculates a negative size, resulting in a segmentation fault crash. This allows an unauthenticated remote attacker to cause a denial of service by crashing the server. The vulnerability is tracked as CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) and CWE-787 (Out-of-bounds Write).
Potential Impact
An unauthenticated attacker who knows the server's IP address and port can remotely crash the FirebirdSQL server, causing a denial of service. There is no indication of confidentiality or integrity impact, but availability is severely affected. No known exploits in the wild have been reported at this time.
Mitigation Recommendations
This vulnerability is fixed in FirebirdSQL versions 5.0.4, 4.0.7, and 3.0.14. Users should upgrade to these or later versions to remediate the issue. Patch status is confirmed by the vendor's versioning information. No other mitigation or workaround is indicated.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-02-24T15:19:29.716Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69e27e0fbdfbbecc5978c94a
Added to database: 4/17/2026, 6:38:07 PM
Last enriched: 4/17/2026, 6:53:27 PM
Last updated: 6/2/2026, 4:42:01 AM
Views: 77
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