CVE-2026-33337 - Firebird has a buffer overflow when parsing corrupted slice packets

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HIGH

Firebird has a buffer overflow when parsing corrupted slice packets

Published Apr 17, 2026

7.5

HIGH

CVSS 3.1

EPSS 0.81%

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.

Affected products

Vendor FirebirdSQL Product Firebird Default
n/a
- Version
  >= 3.0.0, < 3.0.14
  Status
  affected
  Constraints
  -
- Version
  >= 4.0.0, < 4.0.7
  Status
  affected
  Constraints
  -
- Version
  >= 5.0.0, < 5.0.4
  Status
  affected
  Constraints
  -

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor

Product

Default status

Versions

FirebirdSQL

Firebird

n/a

Version	Status	Constraints
>= 3.0.0, < 3.0.14	affected	-
>= 4.0.0, < 4.0.7	affected	-
>= 5.0.0, < 5.0.4	affected	-

Remediation

No remediation recorded yet.

Weaknesses (2)

CWE-120

Classic Buffer Overflow

CWE-502

Deserialization of Untrusted Data

References (5)

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-23482
Advisory
https://github.com/FirebirdSQL/firebird/releases/tag/v3.0.14
x_refsource_MISCRelease Notes
https://github.com/FirebirdSQL/firebird/releases/tag/v4.0.7
x_refsource_MISCRelease Notes
https://github.com/FirebirdSQL/firebird/releases/tag/v5.0.4
x_refsource_MISCRelease Notes
https://github.com/FirebirdSQL/firebird/security/advisories/GHSA-89mq-229g-x47p
x_refsource_CONFIRMExploitVendor Advisory

Link	Providers	Tags
https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-23482		Advisory
https://github.com/FirebirdSQL/firebird/releases/tag/v3.0.14		x_refsource_MISCRelease Notes
https://github.com/FirebirdSQL/firebird/releases/tag/v4.0.7		x_refsource_MISCRelease Notes
https://github.com/FirebirdSQL/firebird/releases/tag/v5.0.4		x_refsource_MISCRelease Notes
https://github.com/FirebirdSQL/firebird/security/advisories/GHSA-89mq-229g-x47p		x_refsource_CONFIRMExploitVendor Advisory