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Vulnerability record · CVE-2025-30342 · published 21 March 2025

CVE-2025-30342: Openslides cross-site scripting vulnerability

Openslides · Openslides

An XSS issue was discovered in OpenSlides before 4.2.5. When submitting descriptions such as Moderator Notes or Agenda Topics, an editor is shown that allows one to format the submitted text. This allows insertion of various HTML elements. When trying to insert a SCRIPT element, it is properly encoded when reflected; however, adding attributes to links is possible, which allows the injection of JavaScript via the onmouseover attribute and others. When a user moves the mouse over such a prepared link, JavaScript is executed in that user's session.

6.1 CVSS 3.1 Medium EPSS 0.26% · top 84.3% CWE-79 · Cross-site scripting
6.1CVSS 3.1 base score
0.26%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
1References, 1 tagged exploit
17 Jun 2026Last modified by NVD

Description

An XSS issue was discovered in OpenSlides before 4.2.5. When submitting descriptions such as Moderator Notes or Agenda Topics, an editor is shown that allows one to format the submitted text. This allows insertion of various HTML elements. When trying to insert a SCRIPT element, it is properly encoded when reflected; however, adding attributes to links is possible, which allows the injection of JavaScript via the onmouseover attribute and others. When a user moves the mouse over such a prepared link, JavaScript is executed in that user's session.

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://www.x41-dsec.de/lab/advisories/x41-2025-001-OpenSlides ExploitThird Party Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2025-30342), CISA KEV, FIRST EPSS (scores of 2026-09-28). This page is refreshed as NVD updates the record.