High severity · published Apr 17, 2026
CVE-2026-33337
Firebird has a buffer overflow when parsing corrupted slice packets
7.5
CVSS
0.5%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 45% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FI
firebird · FirebirdSQL
>= 3.0.0, < 3.0.14; >= 4.0.0, < 4.0.7; >= 5.0.0, < 5.0.4 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-33337
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-33337
Release Notes
https://github.com/FirebirdSQL/firebird/releases/tag/v3.0.14
Release Notes
https://github.com/FirebirdSQL/firebird/releases/tag/v4.0.7
Release Notes
https://github.com/FirebirdSQL/firebird/releases/tag/v5.0.4
Exploit
https://github.com/FirebirdSQL/firebird/security/advisories/GHSA-89mq-229g-x47p
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