Is CVE-2026-27890 in the CISA KEV catalog?

No. CVE-2026-27890 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-27890?

CVE-2026-27890 has a CVSS v3 base score of 8.2 (HIGH).

What is the EPSS score for CVE-2026-27890?

CVE-2026-27890 has an EPSS score of 0.46% (37th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2026-27890

HIGH

8.2

CVSS v3

NVD

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.

CWE-119Buffer Overflow CWE-787Out-of-bounds Write

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityLow

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H

Exploit Intelligence

0.46%probability of exploitation in 30 days

37thpercentile

Low risk: more likely to be exploited than 37% of all known CVEs.

References

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-04-24.