CVE•Published 2026-04-17•Modified 2026-04-24•1 article on news•7 live references•NVD data

CVE-2026-27890Firebirdsql · Firebird

Vulnerability data via NVD (ingested)

CVSS v3.1

8.2

HIGH

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

EPSS percentile

Exploit Prediction Scoring System · top 74% of all CVEs

Weaknesses (CWE)

CWE-119Improper Restriction of Operations within the Bounds of a Memory Buffer CWE-787Out-of-bounds Write

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.

Timeline

Published 2026-04-17

Modified 2026-04-24

External references

NVD MITRE Exploit-DB GitHub PoC Sploitus trickest/cve VulnCheck

Search for exposed instances

Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).

Shodan · vuln tag0 hosts

vuln:CVE-2026-27890

Hosts Shodan has explicitly fingerprinted as vulnerable.

Shodan · product

product:"Firebirdsql Firebird"

All exposed Firebirdsql Firebird instances — cross-reference with the CVE's affected-version range.

Shodan · banner/body mention

http.html:"Firebird"

HTTP body or banner mentions "Firebird" — catches deploys Shodan didn't identify as a product.

More intel sources (5)

Shodan report

vuln:CVE-2026-27890