CVE-2026-33337

Firebird has a buffer overflow when parsing corrupted slice packets

State: Published
Severity: 7.5 High
Published: Apr 17, 2026
Updated: Apr 17, 2026
Reserved: Mar 18, 2026

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 deserializing a slice packet, the xdr_datum() function does not validate that a cstring length conforms to the slice descriptor bounds, allowing a cstring longer than the allocated buffer to overflow it. An unauthenticated attacker can exploit this by sending a crafted packet to the server, potentially causing a crash or other security impact. This issue has been fixed in versions 5.0.4, 4.0.7 and 3.0.14.

Scores

CVSS	Score	Vector	Source
3.1	7.5 High	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H	GitHub_M

Weaknesses

CWE-120 Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
CWE-502 Deserialization of Untrusted Data

Affected Products

Product	Versions
firebirdFirebirdSQL	>= 3.0.0, < 3.0.14Affected >= 4.0.0, < 4.0.7Affected >= 5.0.0, < 5.0.4Affected

References

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