How severe is CVE-2026-33337?

CVE-2026-33337 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-33337 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (42nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-33337?

CVE-2026-33337 affects Firebirdsql Firebird. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-33337?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-33337 have an EU (EUVD) identifier?

Yes. CVE-2026-33337 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-23482.

When was CVE-2026-33337 published?

CVE-2026-33337 was published on 2026-04-17 and last updated on 2026-06-17.

CVE-2026-33337

CVE-2026-33337 is a high-severity vulnerability in Firebirdsql Firebird with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-120.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 1% (42nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-23482
Weakness: CWE-120
Affected product: Firebirdsql Firebird
Published: 2026-04-17
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2026-33337?: 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.
How severe is CVE-2026-33337?: CVE-2026-33337 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-33337 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (42nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-33337?: CVE-2026-33337 affects Firebirdsql Firebird. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-33337?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-33337 have an EU (EUVD) identifier?: Yes. CVE-2026-33337 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-23482.
When was CVE-2026-33337 published?: CVE-2026-33337 was published on 2026-04-17 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:firebirdsql:firebird:*:*:*:*:*:*:*:*

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