Buffer overflow in Firebird - CVE-2026-33337

Vulnerability identifier: #VU126552

CSH Severity: Medium

CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-33337

CWE-ID: CWE-120

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to a buffer overflow in xdr_datum() when parsing a corrupted slice packet. A remote attacker can send a specially crafted slice packet to cause a denial of service.

The issue occurs when a cstring length is not checked against the slice descriptor or the entire slice length before being written into a slice-sized buffer.

Firebird
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Package Hub 15
firebird
firebird-debugsource
libib_util
firebird-examples
libfbclient2
libib_util-debuginfo
firebird-utils
firebird-server
libib_util-devel
libfbclient2-debuginfo
firebird-server-debuginfo
firebird-utils-debuginfo
libfbclient-devel
firebird-debuginfo

Install security update from vendor's website.

Firebird - addressed in versions 3.0.14, 4.0.7, 5.0.4
firebird - update to 3.0.14.33856-150200.3.9.1
firebird-debugsource - update to 3.0.14.33856-150200.3.9.1
libib_util - update to 3.0.14.33856-150200.3.9.1
firebird-examples - update to 3.0.14.33856-150200.3.9.1
libfbclient2 - update to 3.0.14.33856-150200.3.9.1
libib_util-debuginfo - update to 3.0.14.33856-150200.3.9.1
firebird-utils - update to 3.0.14.33856-150200.3.9.1
firebird-server - update to 3.0.14.33856-150200.3.9.1
libib_util-devel - update to 3.0.14.33856-150200.3.9.1
libfbclient2-debuginfo - update to 3.0.14.33856-150200.3.9.1
firebird-server-debuginfo - update to 3.0.14.33856-150200.3.9.1
firebird-utils-debuginfo - update to 3.0.14.33856-150200.3.9.1
libfbclient-devel - update to 3.0.14.33856-150200.3.9.1
firebird-debuginfo - update to 3.0.14.33856-150200.3.9.1

• https://github.com/FirebirdSQL/firebird/security/advisories/GHSA-89mq-229g-x47p

• Multiple vulnerabilities in Firebird
• SUSE update for firebird