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Medium

Security advisory

Type: advisorySources: OSVCVE: 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.

Products
Not specified
Affected versions
Not specified
Fixed versions
Not specified
CVEs
CVE-2025-30342
Confirmed fixed CVEs
Not specified
Updated in this feed
8 Nov 2026, 02:32 UTC · Revision 1

Source evidence

CVE-2025-30342

core-osv · Original source

Published 21 Mar 2025, 00:00 UTC

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.

osv:CVE-2025-30342
Complete source record
{
  "id": "0c27ed28635c463730a5c86ac8b6c1ea24fcffcabe43493ca46782545cfa2581",
  "url": "https://osv.dev/vulnerability/CVE-2025-30342",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2025-30342",
    "summary": "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.",
    "evidence": "osv:CVE-2025-30342",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2025-30342",
      "aliases": [
        "CVE-2025-30342"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/openslides/openslides",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "89d3f5b68366d630219b4d4c4e43c747e7815ec1"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:openslides:openslides:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "4.2.5"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "4.2.4",
            "4.2.3",
            "4.2.2",
            "4.2.1",
            "4.2.0",
            "4.1.22",
            "4.1.21",
            "4.1.20",
            "4.1.19",
            "4.1.18",
            "4.1.17",
            "4.1.16",
            "4.1.15",
            "4.1.14",
            "4.1.13",
            "4.1.12",
            "4.1.11",
            "4.1.7",
            "4.1.0",
            "4.0.0",
            "1.3",
            "1.2",
            "1.1",
            "1.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-30342.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:52.786568694Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/30xxx/CVE-2025-30342.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2025-30342",
        "https://www.x41-dsec.de/lab/advisories/x41-2025-001-OpenSlides"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-79"
        ],
        "cna_assigner": "mitre",
        "unresolved_ranges": [
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "fixed": "4.2.5"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StandardRange"
              }
            ]
          }
        ],
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/30xxx/CVE-2025-30342.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2025-30342",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 521817,
  "published_at": "2025-03-21T00:00:00+00:00"
}