CVE-2026-28803
Open Forms allows users create and publish smart forms. Prior to 3.3.13 and 3.4.5, to be able to cosign, the cosigner receives an e-mail with instructions or a deep-link to start the cosign flow. The submission reference is communicated so that the user can retrieve the submission to be cosigned. Attackers can guess a code or modify the received code to look up arbitrary submissions, after logging in (with DigiD/eHerkenning/... depending on form configuration). This vulnerability is fixed in 3.3.13 and 3.4.5.
Published:Mar 11, 2026
Last Modified:Mar 20, 2026
EPS:Mar 11, 2026
EPSS Score:0.00035
CVSS Score:6.5
Affected Products
Vendor
Product
Action
Vendor
Maykinmedia
Product
Open Forms
Maykinmedia
Open Forms
Vendor
Open-formulieren
Product
Open-forms
Open-formulieren
Open-forms
Exploits
No exploit reference
Common Weakness Enumeration
Common Attack Pattern Enumeration and Classification (CAPEC)
Related CVEs
Common Vulnerability Scoring System
Attack Vector
Network
Adjacent
Local
Physical
Privileges Required
None
Low
High
User Interaction
None
Required
Scope
Unchanged
Changed
Confidentiality
None
Low
High
Integrity
None
Low
High
Availability
None
Low
High
