Is CVE-2026-28803 actively exploited?

No active exploitation of CVE-2026-28803 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-28803 be exploited remotely?

Yes. CVE-2026-28803 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-28803?

CVE-2026-28803 has a CVSS score of 6.5 (MEDIUM).

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MEDIUM

CVE-2026-28803

CWE-284Published: March 11, 2026· Updated: Mar 17, 2026

6.5

CVSS v3.1

EPSS:0.03%probability of exploitation in 30 daysPercentile:7.7th

Official 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.

NVD Source

Technical Analysis

CVE-2026-28803 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in complete confidentiality breach (data exposure), with a CVSS base score of 6.5.