Listen to this Post
The vulnerability, CVE-2026-XXXX, resides in the backend Edit Document Controller’s handling of the `defVals` request parameter during the creation of new records. When a user with edit permissions for a specific database table initiates a record creation request, the controller accepts predefined field values via the `defVals` parameter. The security flaw allows an attacker to inject values into fields marked with `exclude` flags in the User TSconfig or those for which the user lacks explicit edit rights. Normally, backend access controls should sanitize or reject such values. However, the controller improperly merges these attacker-controlled `defVals` with the legitimate form data after the initial permission check, bypassing subsequent field-level validation. This enables the insertion of arbitrary data into protected fields, potentially altering system behavior or privilege boundaries, solely by manipulating the HTTP request parameters sent to the vulnerable endpoint.
DailyCVE Form:
Platform: TYPO3 CMS
Version: 10.0.0-14.0.1
Vulnerability: Broken Access Control
Severity: Moderate
Date: 2026-01-13
Prediction: 2026-01-20
What Undercode Say:
Analytics
`curl -s “https://example.com/typo3/record/edit” –data “defVals[bash][hidden]=1&…”`
`grep -r “defVals” typo3_src/`
`composer show typo3/cms-core | grep version`
How Exploit:
Craft HTTP POST request.
Inject `defVals[bash][excluded_field]`.
Bypass backend validation.
Populate protected exclude fields.
Protection from this CVE:
Update to patched versions.
Validate User TSconfig.
Sanitize `defVals` parameter.
Impact:
Data Integrity Loss.
Privilege Escalation Potential.
Configuration Manipulation.
🎯Let’s Practice Exploiting & Learn Patching For Free:
Sources:
Reported By: github.com
Extra Source Hub:
Undercode
