CVE-2026-28803
Open Forms possible to view submission details of other people than intended
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.
INFO
Published Date :
March 11, 2026, 4:16 p.m.
Last Modified :
March 17, 2026, 7:19 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update Open Forms to version 3.3.13 or 3.4.5.
- Ensure strong authentication mechanisms are used.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-28803.
| URL | Resource |
|---|---|
| https://github.com/open-formulieren/open-forms/security/advisories/GHSA-2g49-rfm6-5qj5 | Mitigation Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-28803 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-28803
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-28803 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-28803 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Mar. 17, 2026
Action Type Old Value New Value Added CWE NVD-CWE-noinfo Added CPE Configuration OR *cpe:2.3:a:maykinmedia:open_forms:*:*:*:*:*:*:*:* versions up to (excluding) 3.3.13 *cpe:2.3:a:maykinmedia:open_forms:*:*:*:*:*:*:*:* versions from (including) 3.4.0 up to (excluding) 3.4.5 Added Reference Type GitHub, Inc.: https://github.com/open-formulieren/open-forms/security/advisories/GHSA-2g49-rfm6-5qj5 Types: Mitigation, Vendor Advisory -
New CVE Received by [email protected]
Mar. 11, 2026
Action Type Old Value New Value Added 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. Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N Added CWE CWE-284 Added Reference https://github.com/open-formulieren/open-forms/security/advisories/GHSA-2g49-rfm6-5qj5