Medium 6.5Published Mar 11, 2026

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

Updated under an hour ago (Oct 27, 2026, 3:50 AM ET)

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It affects open-formulieren open-forms and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for open-formulieren open-forms

Exploited in the last 30 days

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: 6.5 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Weakness (CWE): CWE-284
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Analyzed
Record last updated: Mar 11, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

open-formulieren open-forms open_formulieren:open_forms (from the name)	from 3.4.0-alpha.0, < 3.4.5; before 3.3.13	CNA record
maykinmedia open_forms maykinmedia:open_forms	before 3.3.13; from 3.4.0 before 3.4.5	NVD

References

References

https://github.com/open-formulieren/open-forms/security/advisories/GHSA-2g49-rfm6-5qj5	x-refsource-confirm, mitigation, vendor-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.