CVE-2026-28803 — Open Forms possible to view submission details of other people than intended

Description (CNA)

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.

Affected (CNA)

Vendor / product	Versions
open-formulieren / open-forms	affected >= 3.4.0-alpha.0, < 3.4.5; affected < 3.3.13

CWE

CWE-284

References

https://github.com/open-formulieren/open-forms/security/advisories/GHSA-2g49-rfm6-5qj5

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.