{"document":{"category":"csaf_vex","csaf_version":"2.0","title":"CVE-2026-56278: Flowise - Session Hijacking via Weak Default Express Session Secret","publisher":{"category":"vendor","name":"HarborGuard Database","namespace":"https://database.harborguard.co"},"tracking":{"id":"CVE-2026-56278","status":"final","version":"1","initial_release_date":"2026-06-30T22:08:27.947Z","current_release_date":"2026-06-30T22:08:27.947Z","revision_history":[{"date":"2026-06-30T22:08:27.947Z","number":"1","summary":"Initial machine-readable export from HarborGuard."}]},"distribution":{"tlp":{"label":"WHITE"},"text":"Public CVE data; freely redistributable."},"notes":[{"category":"description","text":"Flowise before 3.1.0 (affected versions 3.0.13 and earlier) uses a weak hardcoded default secret ('flowise') for the express-session middleware when the EXPRESS_SESSION_SECRET environment variable is not set (packages/server/src/enterprise/middleware/passport/index.ts). Because this default secret is publicly visible in the source code, an attacker can forge valid signed session cookies to impersonate any user and bypass authentication.","title":"CVE description"}],"references":[{"category":"self","summary":"CVE-2026-56278 on HarborGuard Database","url":"https://database.harborguard.co/cve/CVE-2026-56278"},{"category":"external","summary":"CVE Record","url":"https://www.cve.org/CVERecord?id=CVE-2026-56278"},{"category":"external","summary":"GitHub Security Advisory (GHSA-2qqc-p94c-hxwh)","url":"https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-2qqc-p94c-hxwh"},{"category":"external","summary":"VulnCheck Advisory: Flowise - Session Hijacking via Weak Default Express Session Secret","url":"https://www.vulncheck.com/advisories/flowise-session-hijacking-via-weak-default-express-session-secret"}]},"product_tree":{"branches":[{"category":"vendor","name":"Flowise","branches":[{"category":"product_name","name":"Flowise","branches":[{"category":"product_version_range","name":"<3.1.0","product":{"name":"Flowise Flowise <3.1.0","product_id":"CSAFPID-1","product_identification_helper":{"cpe":"cpe:2.3:a:flowise:flowise:*:*:*:*:*:*:*:*"}}},{"category":"product_version","name":"3.1.0","product":{"name":"Flowise Flowise 3.1.0","product_id":"CSAFPID-2","product_identification_helper":{"cpe":"cpe:2.3:a:flowise:flowise:*:*:*:*:*:*:*:*"}}}]}]}]},"vulnerabilities":[{"cve":"CVE-2026-56278","title":"Flowise - Session Hijacking via Weak Default Express Session Secret","notes":[{"category":"description","text":"Flowise before 3.1.0 (affected versions 3.0.13 and earlier) uses a weak hardcoded default secret ('flowise') for the express-session middleware when the EXPRESS_SESSION_SECRET environment variable is not set (packages/server/src/enterprise/middleware/passport/index.ts). Because this default secret is publicly visible in the source code, an attacker can forge valid signed session cookies to impersonate any user and bypass authentication.","title":"CVE description"}],"product_status":{"known_affected":["CSAFPID-1"],"fixed":["CSAFPID-2"]},"scores":[{"cvss_v4":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N","baseScore":9.3,"baseSeverity":"CRITICAL"},"products":["CSAFPID-1"]}],"remediations":[{"category":"vendor_fix","details":"Update to a fixed version: 3.1.0.","product_ids":["CSAFPID-1"]}]}]}