XSS in Intevation Openslides

CVE-2025-30342

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.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.003 (15.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 16th percentile — 15.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-30342: held from 0.003 to 0.003.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-30342?
CVE-2025-30342 is a medium-severity vulnerability in Intevation Openslides, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2025-03-21.
How severe is CVE-2025-30342?
Medium severity. CVSS v3 base score is 5.4 out of 10.