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Discourse: Topic featured link susceptible to stored XSS

Type: advisorySources: OSV

Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, a topic "featured link" was not sufficiently normalized and escaped before being rendered in the topic list, allowing a user who can set a featured link to inject JavaScript when default Content Security Policy protections were modified or disabled. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5.

Products
Not specified
Affected versions
Not specified
Fixed versions
Not specified
CVEs
CVE-2026-55424
Confirmed fixed CVEs
Not specified
Updated in this feed
2 Nov 2026, 19:57 UTC · Revision 1

Source evidence

Discourse: Topic featured link susceptible to stored XSS

core-osv · Original source

Published 9 Jul 2026, 22:01 UTC

Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, a topic "featured link" was not sufficiently normalized and escaped before being rendered in the topic list, allowing a user who can set a featured link to inject JavaScript when default Content Security Policy protections were modified or disabled. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5.

osv:CVE-2026-55424
Complete source record
{
  "id": "690700bfd7610efd0a86fda63535efde3b3aea9f9873a8d7fcce2bdf70d0b5fa",
  "url": "https://osv.dev/vulnerability/CVE-2026-55424",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Discourse: Topic featured link susceptible to stored XSS",
    "summary": "Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, a topic \"featured link\" was not sufficiently normalized and escaped before being rendered in the topic list, allowing a user who can set a featured link to inject JavaScript when default Content Security Policy protections were modified or disabled. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5.",
    "evidence": "osv:CVE-2026-55424",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-55424",
      "aliases": [
        "BIT-discourse-2026-55424",
        "CVE-2026-55424",
        "GHSA-695w-7fv8-mxg3"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/discourse/discourse",
              "type": "GIT",
              "events": [
                {
                  "introduced": "322d3c0ac6a8f133b3f82875e9dbbe310f638c1b"
                },
                {
                  "fixed": "c06899647d758493d95a5b301e573ffa3db1e878"
                },
                {
                  "introduced": "fdd750d960e603415db62242eca3c30d68e366db"
                },
                {
                  "fixed": "4bbdddfc6700ca23604242111d4fa0e00347af97"
                },
                {
                  "introduced": "640840d818f4ee9375829ece0ef452923bb0c012"
                },
                {
                  "fixed": "598586ccf2e046a25d4b54132e4e1feb47f24e98"
                },
                {
                  "introduced": "06d03da34c4ed09ea59f917f045ba250d2b6320d"
                },
                {
                  "fixed": "1bce8881e4253d9bbab56f011a12ef899b926b59"
                },
                {
                  "fixed": "6679d9a5083488bae10c2adbb345c481c583242c"
                },
                {
                  "fixed": "6828aee9b15c2655d63b515ac919830bd540ff83"
                },
                {
                  "fixed": "c9b9405f5bd0bf0269e505e28e3aad388d7657c5"
                },
                {
                  "fixed": "06d03da34c4ed09ea59f917f045ba250d2b6320d"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "2026.1.0"
                      },
                      {
                        "fixed": "2026.1.5"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "2026.4.0"
                      },
                      {
                        "fixed": "2026.4.2"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "2026.5.0"
                      },
                      {
                        "fixed": "2026.5.1"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:discourse:discourse:2026.6.0:*:*:*:latest:*:*:*",
                    "range": [
                      {
                        "introduced": "2026.6.0"
                      },
                      {
                        "last_affected": "2026.6.0"
                      }
                    ],
                    "source": "CPE_STRING"
                  },
                  {
                    "range": [
                      {
                        "fixed": "1bce8881e4253d9bbab56f011a12ef899b926b59"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "6679d9a5083488bae10c2adbb345c481c583242c"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "6828aee9b15c2655d63b515ac919830bd540ff83"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "c9b9405f5bd0bf0269e505e28e3aad388d7657c5"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "c06899647d758493d95a5b301e573ffa3db1e878"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v2026.1.5"
                  },
                  {
                    "range": [
                      {
                        "fixed": "4bbdddfc6700ca23604242111d4fa0e00347af97"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v2026.4.2"
                  },
                  {
                    "range": [
                      {
                        "fixed": "598586ccf2e046a25d4b54132e4e1feb47f24e98"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v2026.5.1"
                  },
                  {
                    "range": [
                      {
                        "fixed": "06d03da34c4ed09ea59f917f045ba250d2b6320d"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v2026.6.0"
                  }
                ]
              }
            }
          ],
          "versions": [
            "2026.6.0",
            "v2026.5.0",
            "v2026.1.4",
            "v2026.4.1",
            "v2026.5.0-latest.1",
            "v2026.4.0",
            "v2026.5.0-latest",
            "v2026.1.3",
            "v2026.4.0-latest",
            "v2026.1.2",
            "v2026.1.1",
            "v2026.1.0",
            "stable",
            "esr",
            "v2026.1.0-latest"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-55424.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:23.196515473Z",
      "provider": "osv",
      "references": [
        "https://github.com/discourse/discourse/releases/tag/v2026.1.5",
        "https://github.com/discourse/discourse/releases/tag/v2026.4.2",
        "https://github.com/discourse/discourse/releases/tag/v2026.5.1",
        "https://github.com/discourse/discourse/releases/tag/v2026.6.0",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55424.json",
        "https://github.com/discourse/discourse/security/advisories/GHSA-695w-7fv8-mxg3",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-55424",
        "https://github.com/discourse/discourse/commit/1bce8881e4253d9bbab56f011a12ef899b926b59",
        "https://github.com/discourse/discourse/commit/6679d9a5083488bae10c2adbb345c481c583242c",
        "https://github.com/discourse/discourse/commit/6828aee9b15c2655d63b515ac919830bd540ff83",
        "https://github.com/discourse/discourse/commit/c9b9405f5bd0bf0269e505e28e3aad388d7657c5"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-79"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55424.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-55424",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 489489,
  "published_at": "2026-07-09T22:01:22.249+00:00"
}