CVE-2026-31816
CriticalExploitedPublic exploitBudibase Universal Auth Bypass via Webhook Query Param Injection
Published Mar 9, 2026 · Updated Aug 12, 2026 · Also known as GHSA-gw94-hprh-4wj8
Key Facts
Patch immediately- CVE-2026-31816 is a critical-severity vulnerability (CVSS 9.1 v3.1) affecting Budibase.
- It is exploited in the wild, listed in Industry KEV feed since Jun 5, 2026. Public exploit code is available.
- EPSS estimates a 2.2% probability of exploitation in the next 30 days.
- Fixed versions are available, including Budibase 3.31.4.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
9.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
EPSS (30-day exploit likelihood)
2.2%
Higher than 82.1% of all scored CVEs
Exploited in the wild
Yes
1 catalog listing
Public exploit code
Available
Proof-of-concept or weaponized module
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Description
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.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| Industry KEV feed | Jun 5, 2026 | n/a | Not reported |
Required action: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Affected Products
2 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| BudibaseBudibase | >= <= 3.31.4 | 3.31.4 |
Patched Releases
Budibase
3.31.4
Timeline
Publicly disclosed
Mar 9, 2026
Added to Industry KEV feed
Jun 5, 2026
Last updated
Aug 12, 2026
Weakness Type
- CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
References
FAQ
Common Questions.
Budibase is a low code platform for creating internal tools, workflows, and admin panels.
Affected: Budibase versions >= <= 3.31.4. The full list is in the CVE brief.
It is exploited in the wild, listed in Industry KEV feed since Jun 5, 2026.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
Fixed versions are available, including Budibase 3.31.4.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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