{"id":"CVE-2024-21908","aliases":["CLSA-2026-1777423184","EUVD-2021-2161","GHSA-5h9g-x5rv-25wg","GHSA-5vm8-hhgr-jcjp","UBUNTU-CVE-2024-21908"],"status":"published","title":"Cross-site scripting vulnerability in TinyMCE","description":"TinyMCE versions before 5.9.0 are affected by a stored cross-site scripting vulnerability. An unauthenticated and remote attacker could insert crafted HTML into the editor resulting in arbitrary JavaScript execution in another user's browser.","severity":{"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","from":"nvd"},"epss":{"day":"2026-11-10","score":0.01066,"percentile":0.65029,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-79"],"published":"2021-05-28T19:18:53Z","modified":"2026-10-28T02:30:50Z","fixes":[{"ecosystem":"npm","package":"tinymce","fixed_in":["5.9.0","5.7.1"],"sources":["ghsa","osv"]},{"ecosystem":"NuGet","package":"TinyMCE","fixed_in":["5.9.0"],"sources":["ghsa","osv"]},{"ecosystem":"Packagist","package":"tinymce/tinymce","fixed_in":["5.9.0"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"tinymce","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.9.0"}]}]},{"source":"ghsa","ecosystem":"NuGet","package":"TinyMCE","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.9.0"}]}]},{"source":"ghsa","ecosystem":"Packagist","package":"tinymce/tinymce","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.9.0"}]}]},{"source":"ghsa","ecosystem":"npm","package":"tinymce","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.7.1"}]}]},{"source":"osv","ecosystem":"TuxCare:npm","package":"tinymce","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.9.11-tuxcare.0"},{"fixed":"4.9.11-tuxcare.1"}]}],"versions":["4.9.11"],"bundled":11},{"source":"osv","ecosystem":"npm","package":"tinymce","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"5.9.0"}]}]},{"source":"osv","ecosystem":"NuGet","package":"TinyMCE","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.9.0"}]}],"versions":["3.4.3.2","3.4.4","3.4.5","3.4.7","3.5.0","3.5.0.1","3.5.1","3.5.1.1","3.5.2","3.5.3","3.5.4","3.5.4.1","3.5.5","3.5.6","3.5.7","3.5.8","4.0.0","4.0.1","4.0.10","4.0.11","4.0.13","4.0.14","4.0.15","4.0.16","4.0.17","4.0.18","4.0.19","4.0.2","4.0.20","4.0.21","4.0.22","4.0.23","4.0.24","4.0.25","4.0.26","4.0.27","4.0.28","4.0.4","4.0.5","4.0.6","4.0.8","4.0.9","4.1.0","4.1.1","4.1.10","4.1.2","4.1.3","4.1.4","4.1.5","4.1.6","4.1.7","4.1.8","4.1.9","4.2.0","4.2.1","4.2.2","4.2.3","4.2.4","4.2.5","4.2.6","4.2.7","4.2.8","4.3.0","4.3.1","4.3.10","4.3.11","4.3.12","4.3.13","4.3.2","4.3.3","4.3.4","4.3.6","4.3.7","4.3.8","4.3.9","4.4.0","4.4.1","4.4.2","4.4.3","4.5.0","4.5.1","4.5.2","4.5.3","4.5.4","4.5.5","4.5.6","4.5.7","4.5.8","4.6.0","4.6.1","4.6.2","4.6.3","4.6.4","4.6.5","4.6.6","4.6.7","4.7.0","4.7.10","4.7.11","4.7.12","4.7.13","4.7.3","4.7.4","4.7.5","4.7.6","4.7.7","4.7.8","4.7.9","4.8.0","4.8.1","4.8.2","4.8.3","4.8.4","4.8.5","4.9.0","4.9.1","4.9.10","4.9.11","4.9.2","4.9.3","4.9.4","4.9.5","4.9.6","4.9.7","4.9.8","4.9.9","5.0.0","5.0.1","5.0.10","5.0.11","5.0.12","5.0.13","5.0.14","5.0.15","5.0.16","5.0.2","5.0.3","5.0.4","5.0.5","5.0.6","5.0.7","5.0.8","5.0.9","5.1.0","5.1.1","5.1.2","5.1.3","5.1.4","5.1.5","5.1.6","5.2.0","5.2.1","5.2.2","5.3.0","5.3.1","5.3.2","5.4.0","5.4.1","5.4.2","5.5.0","5.5.1","5.6.0","5.6.1","5.6.2","5.7.0","5.7.1","5.8.0","5.8.1","5.8.2"]},{"source":"osv","ecosystem":"Packagist","package":"tinymce/tinymce","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.9.0"}]}],"versions":["4.0.0","4.0.1","4.0.10","4.0.11","4.0.12","4.0.13","4.0.14","4.0.15","4.0.16","4.0.17","4.0.18","4.0.19","4.0.2","4.0.20","4.0.21","4.0.22","4.0.23","4.0.24","4.0.25","4.0.26","4.0.27","4.0.28","4.0.3","4.0.4","4.0.5","4.0.6","4.0.7","4.0.8","4.0.9","4.1.0","4.1.1","4.1.10","4.1.2","4.1.3","4.1.4","4.1.5","4.1.6","4.1.7","4.1.8","4.1.9","4.2.0","4.2.1","4.2.2","4.2.3","4.2.4","4.2.5","4.2.6","4.2.7","4.2.8","4.3.0","4.3.1","4.3.10","4.3.11","4.3.12","4.3.13","4.3.2","4.3.3","4.3.4","4.3.6","4.3.7","4.3.8","4.3.9","4.4.0","4.4.1","4.4.2","4.4.3","4.5.0","4.5.1","4.5.12","4.5.2","4.5.3","4.5.4","4.5.5","4.5.6","4.5.7","4.5.8","4.5.9","4.6.0","4.6.1","4.6.2","4.6.3","4.6.4","4.6.5","4.6.6","4.6.7","4.7.0","4.7.1","4.7.10","4.7.11","4.7.12","4.7.13","4.7.2","4.7.3","4.7.4","4.7.5","4.7.6","4.7.7","4.7.8","4.7.9","4.8.0","4.8.1","4.8.2","4.8.3","4.8.4","4.8.5","4.9.0","4.9.1","4.9.10","4.9.11","4.9.2","4.9.3","4.9.4","4.9.5","4.9.6","4.9.7","4.9.8","4.9.9","5.0.0","5.0.1","5.0.10","5.0.11","5.0.12","5.0.13","5.0.14","5.0.15","5.0.16","5.0.2","5.0.3","5.0.4","5.0.5","5.0.6","5.0.7","5.0.8","5.0.9","5.1.0","5.1.1","5.1.2","5.1.3","5.1.4","5.1.5","5.1.6","5.2.0","5.2.1","5.2.2","5.3.0","5.3.1","5.3.2","5.4.0","5.4.1","5.4.2","5.5.0","5.5.1","5.6.0","5.6.1","5.6.2","5.7.0","5.7.1","5.8.0","5.8.1","5.8.2"]},{"source":"osv","ecosystem":"npm","package":"tinymce","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"5.7.1"}]}]},{"source":"osv","ecosystem":"Ubuntu:16.04:LTS","package":"tinymce","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.4.8+dfsg0-1"]},{"source":"osv","ecosystem":"Ubuntu:18.04:LTS","package":"tinymce","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.4.8+dfsg0-2"]},{"source":"osv","ecosystem":"Ubuntu:20.04:LTS","package":"tinymce","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.4.8+dfsg0-2"]}],"products":[{"vendor":"tiny","product":"tinymce"}],"references":[{"url":"https://github.com/tinymce/tinymce/security/advisories/GHSA-5h9g-x5rv-25wg","tags":["vendor-advisory","x_transferred","Exploit","Third Party Advisory","advisory","web","report"]},{"url":"https://www.tiny.cloud/docs/release-notes/release-notes59/#securityfixes","tags":["related","x_transferred","Release Notes","web","report"]},{"url":"https://github.com/advisories/GHSA-5h9g-x5rv-25wg","tags":["vendor-advisory","third-party-advisory","x_transferred","Exploit","Third Party Advisory","advisory","report"]},{"url":"https://vulncheck.com/advisories/vc-advisory-GHSA-5h9g-x5rv-25wg","tags":["third-party-advisory","x_transferred","Third Party Advisory","advisory","report"]},{"url":"https://github.com/tinymce/tinymce/security/advisories/GHSA-5vm8-hhgr-jcjp","tags":["web"]},{"url":"https://github.com/advisories/GHSA-5vm8-hhgr-jcjp"},{"url":"https://nuget.org/packages","tags":["web"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/21xxx/CVE-2024-21908.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2024-21908","tags":["advisory"]},{"url":"https://github.com/tinymce/tinymce","tags":["package"]},{"url":"https://ubuntu.com/security/CVE-2024-21908","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2024-21908","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2024-21908","title":"Cross-site scripting vulnerability in TinyMCE","description":"TinyMCE versions before 5.9.0 are affected by a stored cross-site scripting vulnerability. An unauthenticated and remote attacker could insert crafted HTML into the editor resulting in arbitrary JavaScript execution in another user's browser.","status":"published","published":"2024-01-03T15:38:09.664Z","modified":"2026-11-08T13:59:50.839Z","cvss":[{"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":"adp"}],"cwes":["CWE-79"],"updated_at":"2026-11-08T14:43:22.764053Z"}],"euvd":[{"id":"EUVD-2021-2161","description":"TinyMCE versions before 5.9.0 are affected by a stored cross-site scripting vulnerability. An unauthenticated and remote attacker could insert crafted HTML into the editor resulting in arbitrary JavaScript execution in another user's browser.","status":"published","published":"2024-01-03T15:38:09Z","modified":"2026-11-08T13:59:50Z","cvss":[{"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"}],"updated_at":"2026-11-08T15:13:10.25084Z"}],"ghsa":[{"id":"GHSA-5h9g-x5rv-25wg","title":"Cross-site scripting vulnerability in TinyMCE","description":"### Impact\nA cross-site scripting (XSS) vulnerability was discovered in the schema validation logic of the core parser. The vulnerability allowed arbitrary JavaScript execution when inserting a specially crafted piece of content into the editor using the clipboard or editor APIs. This malicious content could then end up in content published outside the editor, if no server-side sanitization was performed. This impacts all users who are using TinyMCE 5.8.2 or lower.\n\n### Patches\nThis vulnerability has been patched in TinyMCE 5.9.0 by ensuring schema validation was still performed after unwrapping invalid elements.\n\n### Workarounds\nTo work around this vulnerability, either:\n- Upgrade to TinyMCE 5.9.0 or higher\n- Manually sanitize the content using the `BeforeSetContent` event (see below)\n\n#### Example: Manually sanitize content\n```js\neditor.on('BeforeSetContent', function(e) {\n  var sanitizedContent = ...; // Manually sanitize content here\n  e.content = sanitizedContent;\n});\n```\n\n### Acknowledgements\nTiny Technologies would like to thank William Bowling for discovering this vulnerability.\n\n### References\nhttps://www.tiny.cloud/docs/release-notes/release-notes59/#securityfixes\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Email us at [infosec@tiny.cloud](mailto:infosec@tiny.cloud)\n* Open an issue in the [TinyMCE repo](https://github.com/tinymce/tinymce/issues)","status":"published","published":"2021-10-22T16:24:02Z","modified":"2024-01-03T22:34:20Z","cvss":[{"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"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:37:29.411214Z"},{"id":"GHSA-5vm8-hhgr-jcjp","title":"Cross-site scripting vulnerability in TinyMCE","description":"### Impact\nA cross-site scripting (XSS) vulnerability was discovered in the URL sanitization logic of the core parser for `form` elements. The vulnerability allowed arbitrary JavaScript execution when inserting a specially crafted piece of content into the editor using the clipboard or APIs, and then submitting the form. However, as TinyMCE does not allow forms to be submitted while editing, the vulnerability could only be triggered when the content was previewed or rendered outside of the editor. This impacts all users who are using TinyMCE 5.7.0 or lower.\n\n### Patches\nThis vulnerability has been patched in TinyMCE 5.7.1 by improved URL sanitization logic.\n\n### Workarounds\nTo work around this vulnerability, either:\n- Upgrade to TinyMCE 5.7.1 or higher\n- Manually sanitize `form` URL attributes using a [TinyMCE node filter](https://www.tiny.cloud/docs/api/tinymce.html/tinymce.html.domparser/#addnodefilter).\n- Disable `form` elements in your content using the [invalid_elements](https://www.tiny.cloud/docs/configure/content-filtering/#invalid_elements) setting.\n\n#### Example: Sanitizing using a node filter\n```js\neditor.parser.addNodeFilter('form', function(nodes) {\n  nodes.forEach(function(node) {\n    if (node.attributes) {\n      node.attributes.forEach(function(attr) {\n        var name = attr.name;\n        var value = attr.value;\n        // Sanitize the attribute value here or remove it entirely\n        var sanitizedValue = ...;\n        node.attr(name, santizedValue);\n      });\n    }\n  });\n});\n```\n\n#### Example: Using invalid_elements\n```js\ninvalid_elements: 'form'\n```\n\n### Acknowledgements\nTiny Technologies would like to thank Mikhail Khramenkov at Solar Security Research Team for discovering this vulnerability.\n\n### References\nhttps://www.tiny.cloud/docs/release-notes/release-notes571/#securityfixes\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in the [TinyMCE repo](https://github.com/tinymce/tinymce/issues)\n* Email us at [infosec@tiny.cloud](mailto:infosec@tiny.cloud)","status":"published","published":"2021-05-28T19:18:53Z","modified":"2023-01-09T05:05:07Z","cwes":["CWE-79"],"updated_at":"2026-11-02T14:36:11.367194Z"}],"nvd":[{"id":"CVE-2024-21908","description":"TinyMCE versions before 5.9.0 are affected by a stored cross-site scripting vulnerability. An unauthenticated and remote attacker could insert crafted HTML into the editor resulting in arbitrary JavaScript execution in another user's browser.","status":"published","published":"2024-01-03T16:15:08.913Z","modified":"2026-07-14T23:17:14.113Z","cvss":[{"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"},{"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":"secondary"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:09:30.070039Z"}],"osv":[{"id":"CVE-2024-21908","title":"Cross-site scripting vulnerability in TinyMCE","description":"TinyMCE versions before 5.9.0 are affected by a stored cross-site scripting vulnerability. An unauthenticated and remote attacker could insert crafted HTML into the editor resulting in arbitrary JavaScript execution in another user's browser.","status":"published","published":"2024-01-03T15:38:09.664Z","modified":"2026-11-09T02:31:01.221683731Z","cvss":[{"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"}],"cwes":["CWE-79"],"updated_at":"2026-11-09T03:16:44.651171Z"},{"id":"GHSA-5h9g-x5rv-25wg","title":"Cross-site scripting vulnerability in TinyMCE","description":"### Impact\nA cross-site scripting (XSS) vulnerability was discovered in the schema validation logic of the core parser. The vulnerability allowed arbitrary JavaScript execution when inserting a specially crafted piece of content into the editor using the clipboard or editor APIs. This malicious content could then end up in content published outside the editor, if no server-side sanitization was performed. This impacts all users who are using TinyMCE 5.8.2 or lower.\n\n### Patches\nThis vulnerability has been patched in TinyMCE 5.9.0 by ensuring schema validation was still performed after unwrapping invalid elements.\n\n### Workarounds\nTo work around this vulnerability, either:\n- Upgrade to TinyMCE 5.9.0 or higher\n- Manually sanitize the content using the `BeforeSetContent` event (see below)\n\n#### Example: Manually sanitize content\n```js\neditor.on('BeforeSetContent', function(e) {\n  var sanitizedContent = ...; // Manually sanitize content here\n  e.content = sanitizedContent;\n});\n```\n\n### Acknowledgements\nTiny Technologies would like to thank William Bowling for discovering this vulnerability.\n\n### References\nhttps://www.tiny.cloud/docs/release-notes/release-notes59/#securityfixes\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Email us at [infosec@tiny.cloud](mailto:infosec@tiny.cloud)\n* Open an issue in the [TinyMCE repo](https://github.com/tinymce/tinymce/issues)","status":"published","published":"2021-10-22T16:24:02Z","modified":"2026-07-08T06:52:56.328447513Z","cvss":[{"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"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T15:46:38.553953Z"},{"id":"UBUNTU-CVE-2024-21908","description":"TinyMCE versions before 5.9.0 are affected by a stored cross-site scripting vulnerability. An unauthenticated and remote attacker could insert crafted HTML into the editor resulting in arbitrary JavaScript execution in another user's browser.","status":"published","published":"2024-01-03T16:15:00Z","modified":"2025-10-24T05:06:51Z","cvss":[{"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"},{"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"}],"updated_at":"2026-11-02T16:54:42.68848Z"},{"id":"CLSA-2026-1777423184","title":"TuxCare security update for tinymce (12 CVEs)","description":"TuxCare rebuilt tinymce to address 12 CVEs. Fixed in 4.9.11-tuxcare.1.","status":"published","published":"2026-08-04T14:52:29Z","modified":"2026-10-23T13:58:18.137089536Z","updated_at":"2026-11-02T15:43:44.384419Z"},{"id":"GHSA-5vm8-hhgr-jcjp","title":"Cross-site scripting vulnerability in TinyMCE","description":"### Impact\nA cross-site scripting (XSS) vulnerability was discovered in the URL sanitization logic of the core parser for `form` elements. The vulnerability allowed arbitrary JavaScript execution when inserting a specially crafted piece of content into the editor using the clipboard or APIs, and then submitting the form. However, as TinyMCE does not allow forms to be submitted while editing, the vulnerability could only be triggered when the content was previewed or rendered outside of the editor. This impacts all users who are using TinyMCE 5.7.0 or lower.\n\n### Patches\nThis vulnerability has been patched in TinyMCE 5.7.1 by improved URL sanitization logic.\n\n### Workarounds\nTo work around this vulnerability, either:\n- Upgrade to TinyMCE 5.7.1 or higher\n- Manually sanitize `form` URL attributes using a [TinyMCE node filter](https://www.tiny.cloud/docs/api/tinymce.html/tinymce.html.domparser/#addnodefilter).\n- Disable `form` elements in your content using the [invalid_elements](https://www.tiny.cloud/docs/configure/content-filtering/#invalid_elements) setting.\n\n#### Example: Sanitizing using a node filter\n```js\neditor.parser.addNodeFilter('form', function(nodes) {\n  nodes.forEach(function(node) {\n    if (node.attributes) {\n      node.attributes.forEach(function(attr) {\n        var name = attr.name;\n        var value = attr.value;\n        // Sanitize the attribute value here or remove it entirely\n        var sanitizedValue = ...;\n        node.attr(name, santizedValue);\n      });\n    }\n  });\n});\n```\n\n#### Example: Using invalid_elements\n```js\ninvalid_elements: 'form'\n```\n\n### Acknowledgements\nTiny Technologies would like to thank Mikhail Khramenkov at Solar Security Research Team for discovering this vulnerability.\n\n### References\nhttps://www.tiny.cloud/docs/release-notes/release-notes571/#securityfixes\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in the [TinyMCE repo](https://github.com/tinymce/tinymce/issues)\n* Email us at [infosec@tiny.cloud](mailto:infosec@tiny.cloud)","status":"published","published":"2021-05-28T19:18:53Z","modified":"2021-05-27T21:29:43Z","cwes":["CWE-79"],"updated_at":"2026-11-02T15:46:38.911014Z"}]}}