CVE-2026-41428: Budibase: Authentication Bypass via Unanchored Regex in Public Endpoint Matcher — Unauthenticated Access to Protected Endpoints
Noroxi assessment
Priority: Monitor (action score 36/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.44% (FIRST EPSS).
- Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
- Fixed version: Budibase budibase 3.35.4.
Low priority for now. Upgrade to Budibase budibase 3.35.4 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
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.
- Published
- Apr 24, 2026
- Updated
- Jun 17, 2026
- EPSS
- 0.4% · 38th percentile
- CWE
- CWE-287
Report tools
Action score
36
Monitor
Low priority for now.
- CVSS
- 36 / 40 · 9.1 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.4%
CISA SSVC decision
- Exploitation
- proof of concept
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · GitHub_M
- 9.1
- NVD has not scored this yet; the score shown is the CNA’s.
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| budibase | budibase | cpe:2.3:a:budibase:budibase |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- budibase budibasebefore 3.35.4
Versions reported by the vendor
Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.
Budibase budibase
- < 3.35.4affected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| npm | @budibase/backend-core | up to and including 3.35.3 | — |
Same product
budibase: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-31816Budibase Universal Auth Bypass via Webhook Query Param Injection41Plan
- CVE-2026-54350Budibase: Anonymous NoSQL operator injection via published-app query templates39Monitor
- CVE-2026-46425Budibase: SCIM endpoints lack role-based authorization, BASIC users CRUD tenant users39Monitor
Published before and after this one in the same product
- ← EarlierCVE-2026-35214Apr 3, 2026 · Budibase: Path traversal in plugin file upload enables arbitrary directory deletion and file write34Monitor
- ← EarlierCVE-2026-35216Apr 3, 2026 · Budibase: Unauthenticated Remote Code Execution via Webhook Trigger and Bash Automation Step39Monitor
- Later →CVE-2026-42239May 7, 2026 · Budibase auth session cookies are set with httpOnly:false — any XSS can lead to full account takeover32Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Budibase budibase | 3.35.4 · description | Vendor (CNA) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
No history yet (it accumulates with the daily EPSS job).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2026-73302111 days apartBudibase: OIDC SSO account takeover: incoming identity linked by email without checking email_verified36Monitor
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
- CVE-2026-3181821 days apartBudibase: Server-Side Request Forgery via REST Connector with Empty Default Blacklist39Monitor
- CVE-2026-2504421 days apartBudibase: Command Injection in Bash Automation Step34Monitor
- CVE-2026-3521421 days apartBudibase: Path traversal in plugin file upload enables arbitrary directory deletion and file write34Monitor
- CVE-2026-4814633 days apartBudibase: SSRF via OAuth2 Config Validation — Missing fetchWithBlacklist Protection30Monitor
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-287 · Improper AuthenticationCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
nvd-secondary
Root cause
Authentication is added route by route instead of being enforced in one place. When a route added later bypasses the shared middleware, the session check never runs for it.
The bug in code
The whole CWE-287 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
app.use("/admin", requireSession, adminRouter);
// Route added later skips the middleware
app.post("/admin-api/config", updateConfig);Fixed
const admin = express.Router();
admin.use(requireSession, requireRole("admin"));
admin.post("/config", updateConfig);
app.use("/admin", admin);Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Authentication AbuseCAPEC-114Medium
- Authentication BypassCAPEC-115Medium
- Identity SpoofingCAPEC-151likelihood: Medium · Medium
- Fake the Source of DataCAPEC-194Medium
- Exploiting Trust in ClientCAPEC-22likelihood: High · High
- Utilizing REST's Trust in the System Resource to Obtain Sensitive DataCAPEC-57likelihood: Medium · Very High
- Session HijackingCAPEC-593likelihood: High · Very High
- Token ImpersonationCAPEC-633Medium
ATT&CK techniques
Change log
- Fix✗ → ✓
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