{"identifier":"CVE-2026-27890","cve":{"id":"CVE-2026-27890","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.","published":"2026-04-17T19:16:34.993000+00:00","modified":"2026-10-26T21:10:00.170000+00:00","status":"Analyzed","score":8.2,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H","cvss_version":"3.1","affected":[{"criteria":"cpe:2.3:a:firebirdsql:firebird:*:*:*:*:*:*:*:*","versionStartIncluding":"","versionStartExcluding":"","versionEndIncluding":"","versionEndExcluding":"3.0.14"},{"criteria":"cpe:2.3:a:firebirdsql:firebird:*:*:*:*:*:*:*:*","versionStartIncluding":"4.0.0","versionStartExcluding":"","versionEndIncluding":"","versionEndExcluding":"4.0.7"},{"criteria":"cpe:2.3:a:firebirdsql:firebird:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0.0","versionStartExcluding":"","versionEndIncluding":"","versionEndExcluding":"5.0.4"}],"weaknesses":["CWE-119","CWE-787"],"references":[{"url":"https://github.com/FirebirdSQL/firebird/releases/tag/v3.0.14","source":"security-advisories@github.com","tags":["Release Notes"]},{"url":"https://github.com/FirebirdSQL/firebird/releases/tag/v4.0.7","source":"security-advisories@github.com","tags":["Release Notes"]},{"url":"https://github.com/FirebirdSQL/firebird/releases/tag/v5.0.4","source":"security-advisories@github.com","tags":["Release Notes"]},{"url":"https://github.com/FirebirdSQL/firebird/security/advisories/GHSA-6crx-4g37-7j49","source":"security-advisories@github.com","tags":["Exploit","Vendor Advisory"]}],"kev":null,"kev_checked":true,"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H","baseScore":8.2,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"LOW","availabilityImpact":"HIGH"},"exploitabilityScore":3.9,"impactScore":4.2}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-04-17T18:50:13.916401Z","id":"CVE-2026-27890","options":[{"exploitation":"poc"},{"automatable":"yes"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:firebirdsql:firebird:*:*:*:*:*:*:*:*","versionEndExcluding":"3.0.14","matchCriteriaId":"53D811A2-F880-46E9-9F7F-1CE3AC487F67"},{"vulnerable":true,"criteria":"cpe:2.3:a:firebirdsql:firebird:*:*:*:*:*:*:*:*","versionStartIncluding":"4.0.0","versionEndExcluding":"4.0.7","matchCriteriaId":"A4BC24D2-FBF7-4308-9914-6079DBDF88FA"},{"vulnerable":true,"criteria":"cpe:2.3:a:firebirdsql:firebird:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0.0","versionEndExcluding":"5.0.4","matchCriteriaId":"938978A3-90BE-4223-BDFC-5310A7C78D9B"}]}]}],"source":"nvd","retrieved_at":"2026-10-28T10:19:12.534245+00:00","exploited":false,"kev_stale":false,"products":["firebirdsql / firebird"],"priority":{"label":"Assess exposure and vendor guidance","reasons":["No higher-priority signal is available in the current stored evidence."]},"epss":{"probability":0.00465,"percentile":0.40209,"date":"2026-10-29","stale":false},"version_assessment":null},"news":[],"campaigns":[],"domains":[{"domain":"github.com","source_url":"https://github.com/FirebirdSQL/firebird/releases/tag/v3.0.14","investigate_url":"https://investigate.aeglixmind.com/#github.com"}],"arsenal_url":"https://arsenal.aeglixmind.com/?cve=CVE-2026-27890","catalog_url":"https://cves.aeglixmind.com/cve/CVE-2026-27890","research_url":"https://investigate.aeglixmind.com/research/cve/CVE-2026-27890","coverage":{"news_candidates_checked":0,"campaign_candidates_checked":0,"bounded":false,"notice":"Exact CVE mentions in stored public excerpts and reviewed campaign content only. A mention is not proof of exploitation, attribution or tool suitability. Missing matches do not establish absence."}}