CVE-2026-28803
Open Forms allows users create and publish smart forms.
Does this matter?
Lower severity and a low EPSS score (0.20%). Track it; it rarely justifies an emergency change on its own.
Description
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.
- CVSS 3.1
- 6.5 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
- EPSS
- 0.20% probability · 10th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-284
- Affected
- maykinmedia/open forms
- Source
- security-advisories@github.com
References
- https://github.com/open-formulieren/open-forms/security/advisories/GHSA-2g49-rfm6-5qj5Mitigation, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.