{"id":"CVE-2023-43658","aliases":["EUVD-2023-48047","GHSA-3fwj-f6ww-7hr6"],"status":"published","title":"Improper escaping of user input in discourse-calendar","description":"dicourse-calendar is a plugin for the Discourse messaging platform which adds the ability to create a dynamic calendar in the first post of a topic. Improper escaping of event titles could lead to Cross-site Scripting (XSS) within the 'email preview' UI when a site has CSP disabled. Having CSP disabled is a non-default configuration, so the vast majority of sites are unaffected. This problem is resolved in the latest version of the discourse-calendar plugin. Users are advised to upgrade. Users unable to upgrade should ensure CSP is enabled on the forum.","severity":{"version":"3.1","score":8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00591,"percentile":0.4854,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-79"],"published":"2023-10-16T21:28:57Z","modified":"2026-10-28T02:31:00Z","products":[{"vendor":"discourse","product":"discourse-calendar"},{"vendor":"discourse","product":"discourse_calendar"}],"references":[{"url":"https://github.com/discourse/discourse-calendar/security/advisories/GHSA-3fwj-f6ww-7hr6","tags":["x_refsource_CONFIRM","x_transferred","Vendor Advisory","advisory"]},{"url":"https://github.com/discourse/discourse-calendar/commit/9788310906febb36822d6823d14f1059c39644de","tags":["x_refsource_MISC","x_transferred","Patch","fix"]},{"url":"https://developer.mozilla.org/en-US/docs/Web/HTTP/CSP","tags":["x_refsource_MISC","x_transferred","Third Party Advisory","web"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/43xxx/CVE-2023-43658.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2023-43658","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2023-43658","title":"Improper escaping of user input in discourse-calendar","description":"dicourse-calendar is a plugin for the Discourse messaging platform which adds the ability to create a dynamic calendar in the first post of a topic. Improper escaping of event titles could lead to Cross-site Scripting (XSS) within the 'email preview' UI when a site has CSP disabled. Having CSP disabled is a non-default configuration, so the vast majority of sites are unaffected. This problem is resolved in the latest version of the discourse-calendar plugin. Users are advised to upgrade. Users unable to upgrade should ensure CSP is enabled on the forum.","status":"published","published":"2023-10-16T21:28:57.341Z","modified":"2024-09-16T15:48:22.849Z","cvss":[{"version":"3.1","score":8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:35:14.298866Z"}],"euvd":[{"id":"EUVD-2023-48047","description":"dicourse-calendar is a plugin for the Discourse messaging platform which adds the ability to create a dynamic calendar in the first post of a topic. Improper escaping of event titles could lead to Cross-site Scripting (XSS) within the 'email preview' UI when a site has CSP disabled. Having CSP disabled is a non-default configuration, so the vast majority of sites are unaffected. This problem is resolved in the latest version of the discourse-calendar plugin. Users are advised to upgrade. Users unable to upgrade should ensure CSP is enabled on the forum.","status":"published","published":"2023-10-16T21:28:57Z","modified":"2024-09-16T15:48:22Z","cvss":[{"version":"3.1","score":8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-03T00:55:54.473264Z"}],"nvd":[{"id":"CVE-2023-43658","description":"dicourse-calendar is a plugin for the Discourse messaging platform which adds the ability to create a dynamic calendar in the first post of a topic. Improper escaping of event titles could lead to Cross-site Scripting (XSS) within the 'email preview' UI when a site has CSP disabled. Having CSP disabled is a non-default configuration, so the vast majority of sites are unaffected. This problem is resolved in the latest version of the discourse-calendar plugin. Users are advised to upgrade. Users unable to upgrade should ensure CSP is enabled on the forum.","status":"published","published":"2023-10-16T22:15:12.143Z","modified":"2026-06-17T06:26:10.34Z","cvss":[{"version":"3.1","score":8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"secondary"},{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:08:37.83429Z"}],"osv":[{"id":"CVE-2023-43658","title":"Improper escaping of user input in discourse-calendar","description":"dicourse-calendar is a plugin for the Discourse messaging platform which adds the ability to create a dynamic calendar in the first post of a topic. Improper escaping of event titles could lead to Cross-site Scripting (XSS) within the 'email preview' UI when a site has CSP disabled. Having CSP disabled is a non-default configuration, so the vast majority of sites are unaffected. This problem is resolved in the latest version of the discourse-calendar plugin. Users are advised to upgrade. Users unable to upgrade should ensure CSP is enabled on the forum.","status":"published","published":"2023-10-16T21:28:57.341Z","modified":"2026-10-28T02:31:00.734599785Z","cvss":[{"version":"3.1","score":8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T15:44:33.792101Z"}]}}