Vulnerability in Budibase

CVE-2026-31816

Budibase is a low code platform for creating internal tools, workflows, and admin panels. In 3.31.4 and earlier, the Budibase server's authorized() middleware that protects every server-side API endpoint can be completely bypassed by appending a webhook path pattern to the query string of any request. The isWebhookEndpoint() function uses an unanchored regex that tests against ctx.request.url, which in Koa includes the full URL with query parameters. When the regex matches, the authorized() middleware immediately calls return next(), skipping all authentication, authorization, role checks, and CSRF protection. This means a completely unauthenticated, remote attacker can access any server-side API endpoint by simply appending ?/webhooks/trigger (or any webhook pattern variant) to the URL.

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:H/A:N.

EPSS exploit prediction

EPSS: 0.022 (81.8th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 82nd percentile — 81.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-31816: fell from 0.153 to 0.022.

EPSS over last 30 days · oldest: 0.153 · newest: 0.022 · change: -0.131

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2026-31816?
CVE-2026-31816 is a critical-severity vulnerability in Budibase, classified under Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection). CVSS score: 9.1/10. Published 2026-03-09.
How severe is CVE-2026-31816?
Critical severity. CVSS v3 base score is 9.1 out of 10.
Is CVE-2026-31816 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.