Auth bypass in Budibase Server
CVE-2026-100684
Budibase versions 3.41.0 before 3.45.0 contain an authentication bypass in the OIDC/SSO login path of @budibase/server. In sso.authenticate, when no existing user matches the incoming SSO subject, the server looks up pending user invites by the IdP-asserted email address alone — without validating an invite code and without an email_verified check (the email_verified gate protects only the existing-account lookup). An attacker who can register at an IdP that the tenant trusts for OIDC and assert a victim's invited email address (even with email_verified=false) claims the pending invite and inherits all of its granted privileges, including builder and admin.global, with no admin exclusion. This results in takeover of the invited principal and, for admin invites, full tenant compromise (access to all apps, datasources including production credentials, and automations); the invite is consumed, denying onboarding to the legitimate invitee.
Vulnerability class: Broken Authentication
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.004 (36.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 36th percentile — 36.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001
Affected products
Weakness classification (CWE)
References
- GitHub Security Advisory (GHSA-35ch-57g2-3g98) (vendor-advisory)
- VulnCheck Advisory: Budibase Server 3.41.0 before 3.45.0 Authentication Bypass via OIDC (third-party-advisory)
Frequently asked questions
- What is CVE-2026-100684?
- CVE-2026-100684 is a high-severity vulnerability in Budibase Server, classified under Improper Authentication. CVSS score: 8.1/10. Published 2026-09-26.
- How severe is CVE-2026-100684?
- High severity. CVSS v3 base score is 8.1 out of 10.