Bug 2459246 (CVE-2026-27890)

Summary: CVE-2026-27890 Firebird: Firebird: Denial of Service via out-of-order authentication segments
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedKeywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in Firebird, an open-source relational database management system. An unauthenticated attacker can exploit this by sending specially crafted authentication segments that arrive out of order. This can cause the server to crash, leading to a Denial of Service (DoS).
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2459255, 2459257    
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Description OSIDB Bzimport 2026-04-17 19:01:44 UTC
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.