How severe is CVE-2026-27890?

CVE-2026-27890 has a CVSS 3.x base score of 8.2, 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 low, and availability high.

Is CVE-2026-27890 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-27890?

CVE-2026-27890 affects Firebirdsql Firebird. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-27890?

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-2026-27890 have an EU (EUVD) identifier?

Yes. CVE-2026-27890 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-23460.

When was CVE-2026-27890 published?

CVE-2026-27890 was published on 2026-04-17 and last updated on 2026-06-17.

CVE-2026-27890

CVE-2026-27890 is a high-severity vulnerability in Firebirdsql Firebird with a CVSS 3.x base score of 8.2. 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-119.

Key facts

Severity: High (CVSS 3.x base score 8.2)
EPSS exploit prediction: 1% (52nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-23460
Weakness: CWE-119
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 processing CNCT_specific_data segments during authentication, the server assumes segments arrive in strictly ascending order. If segments arrive out of order, the Array class's grow() method computes a negative size value, causing a SIGSEGV crash. An unauthenticated attacker who knows only the server's IP and port can exploit this to crash the server. This issue has been fixed in versions 5.0.4, 4.0.7 and 3.0.14.

Frequently asked questions

What is CVE-2026-27890?: Firebird is an open-source relational database management system. In versions prior to 5.0.4, 4.0.7 and 3.0.14, when processing CNCT_specific_data segments during authentication, the server assumes segments arrive in strictly ascending order. If segments arrive out of order, the Array class's grow() method computes a negative size value, causing a SIGSEGV crash. An unauthenticated attacker who knows only the server's IP and port can exploit this to crash the server. This issue has been fixed in versions 5.0.4, 4.0.7 and 3.0.14.
How severe is CVE-2026-27890?: CVE-2026-27890 has a CVSS 3.x base score of 8.2, 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 low, and availability high.
Is CVE-2026-27890 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-27890?: CVE-2026-27890 affects Firebirdsql Firebird. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-27890?: 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-2026-27890 have an EU (EUVD) identifier?: Yes. CVE-2026-27890 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-23460.
When was CVE-2026-27890 published?: CVE-2026-27890 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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