Auth bypass in Budibase
CVE-2026-41428
Budibase is an open-source low-code platform. Prior to 3.35.4, the authenticated middleware uses unanchored regular expressions to match public (no-auth) endpoint patterns against ctx.request.url. Since ctx.request.url in Koa includes the query string, an attacker can access any protected endpoint by appending a public endpoint path as a query parameter. For example, POST /api/global/users/search?x=/api/system/status bypasses all authentication because the regex /api/system/status/ matches in the query string portion of the URL. This vulnerability is fixed in 3.35.4.
Vulnerability class: Broken Authentication
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H.
EPSS exploit prediction
EPSS: 0.006 (48.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 48th percentile — 48.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.006 · change: +0.002
Affected products
- Budibase — versions < 3.35.4
Weakness classification (CWE)
References
- github.com/Budibase/budibase/security/advisories/GHSA-8783-3wgf-jggf (Exploit, Mitigation, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-41428?
- CVE-2026-41428 is a critical-severity vulnerability in Budibase, classified under Improper Authentication. CVSS score: 9.1/10. Published 2026-04-24.
- How severe is CVE-2026-41428?
- Critical severity. CVSS v3 base score is 9.1 out of 10.