Auth bypass in Baserow
CVE-2026-81335
Baserow dispatches an Application Builder data source without acting on the result of its permission check. The dispatch and record-name views in backend/src/baserow/contrib/builder/api/data_sources/views.py are declared with a permission class that admits any caller, so a request carrying no credential reaches the handler. DataSourceService.dispatch_data_sources in backend/src/baserow/contrib/builder/data_sources/service.py then calls check_multiple_permissions without asking it to raise, and neither stores nor examines the mapping of denials it returns, so a denied check leaves execution to continue and the data source is dispatched whatever the caller's identity. The dispatch runs with the integration's own credentials, so an unauthenticated request naming a data source receives the rows and fields that source reads. Identifiers are small integers and can be enumerated. Version 2.3.1 passes raise_exception to the same call.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.006 (45.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 46th percentile — 45.8% 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
Weakness classification (CWE)
References
- baserow.io (product)
- github.com/bram2w/baserow (product)
- github.com/bram2w/baserow/blob/2.3.0/backend/src/baserow/contrib/builder/data_s… (technical-description)
- github.com/bram2w/baserow/blob/2.3.1/backend/src/baserow/contrib/builder/data_s… (patch)
- www.vulncheck.com/advisories/baserow-before-2.3.1-unauthenticated-data-disclosu… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-81335?
- CVE-2026-81335 is a high-severity vulnerability in Baserow, classified under Missing Authorization. CVSS score: 7.5/10. Published 2026-08-27.
- How severe is CVE-2026-81335?
- High severity. CVSS v3 base score is 7.5 out of 10.