{"id":"CVE-2021-32641","aliases":["EUVD-2021-1348","GHSA-jr3j-whm4-9wwm"],"status":"published","title":"Reflected XSS when using flashMessages","description":"auth0-lock is Auth0's signin solution. Versions of nauth0-lock before and including `11.30.0` are vulnerable to reflected XSS. An attacker can execute arbitrary code when the library's `flashMessage` feature is utilized and user input or data from URL parameters is incorporated into the `flashMessage` or the library's `languageDictionary` feature is utilized and user input or data from URL parameters is incorporated into the `languageDictionary`. The vulnerability is patched in version 11.30.1.","severity":{"version":"3.1","score":8.1,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.01539,"percentile":0.75106,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-79"],"published":"2021-06-04T19:10:34Z","modified":"2026-10-20T10:53:45Z","fixes":[{"ecosystem":"npm","package":"auth0-lock","fixed_in":["11.30.1"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"auth0-lock","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"11.30.1"}]}]},{"source":"osv","ecosystem":"npm","package":"auth0-lock","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"11.30.1"}]}]}],"products":[{"vendor":"auth0","product":"lock"}],"references":[{"url":"https://github.com/auth0/lock/security/advisories/GHSA-jr3j-whm4-9wwm","tags":["x_refsource_CONFIRM","x_transferred","Exploit","Third Party Advisory","evidence","web"]},{"url":"https://github.com/auth0/lock/commit/d139cf01c8234b07caf265e051f39d3eab08f7ed","tags":["x_refsource_MISC","x_transferred","Patch","Third Party Advisory","fix","web"]},{"url":"https://github.com/auth0/lock/releases/tag/v11.30.1","tags":["x_refsource_MISC","x_transferred","Release Notes","Third Party Advisory","advisory","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-32641","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-jr3j-whm4-9wwm"}],"sources":{"cve":[{"id":"CVE-2021-32641","title":"Reflected XSS when using flashMessages","description":"auth0-lock is Auth0's signin solution. Versions of nauth0-lock before and including `11.30.0` are vulnerable to reflected XSS. An attacker can execute arbitrary code when the library's `flashMessage` feature is utilized and user input or data from URL parameters is incorporated into the `flashMessage` or the library's `languageDictionary` feature is utilized and user input or data from URL parameters is incorporated into the `languageDictionary`. The vulnerability is patched in version 11.30.1.","status":"published","published":"2021-06-04T21:10:11Z","modified":"2024-08-03T23:25:31.021Z","cvss":[{"version":"3.1","score":8.1,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:33:07.014772Z"}],"euvd":[{"id":"EUVD-2021-1348","description":"auth0-lock is Auth0's signin solution. Versions of nauth0-lock before and including `11.30.0` are vulnerable to reflected XSS. An attacker can execute arbitrary code when the library's `flashMessage` feature is utilized and user input or data from URL parameters is incorporated into the `flashMessage` or the library's `languageDictionary` feature is utilized and user input or data from URL parameters is incorporated into the `languageDictionary`. The vulnerability is patched in version 11.30.1.","status":"published","published":"2021-06-04T21:10:11Z","modified":"2024-08-03T23:25:31Z","cvss":[{"version":"3.1","score":8.1,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-03T03:24:36.41075Z"}],"ghsa":[{"id":"GHSA-jr3j-whm4-9wwm","title":"Reflected XSS when using flashMessages or languageDictionary","description":"### Overview\n\nVersions before and including `11.30.0` are vulnerable to reflected XSS.  An attacker can execute arbitrary code when the library's\n- `flashMessage` feature is utilized and user input or data from URL parameters is incorporated into the `flashMessage`.\n- `languageDictionary` feature is utilized and user input or data from URL parameters is incorporated into the `languageDictionary`.\n\n### Am I affected?\nYou are affected by this vulnerability if you are using `auth0-lock` version `11.30.0` or lower and all of the following conditions apply:\n\n- You are utilizing `flashMessage` feature.\n- User input or data from URL parameters is incorporated into the `flashMessage`.\n\nAn example of a vulnerable snippet where query parameters are used to populate the `text` property of a `flashMessage`.\n```js\nvar params = new URLSearchParams(location.search);\nvar errorMessage = params.get('error__message');\nvar showParams = {};\n\nif (!!errorMessage === true) {\n  showParams.flashMessage = {\n    type: 'error',\n    text: 'We were unable to log you in. ' + errorMessage,\n  };\n}\n\nlock.show(showParams);\n```\n\nOR\n\n- You are utilizing `languageDictionary` feature.\n- User input or data from URL parameters is used in `languageDictionary` properties.\n\nAn example of a vulnerable snippet where query parameters are used to populate the `socialLoginInstructions` property of a `languageDictionary`.\n```js\nvar params = new URLSearchParams(location.search);\nvar instruction = params.get('instruction');\n\nvar options = {\n  languageDictionary: {\n    emailInputPlaceholder: \"something@youremail.com\",\n    title: \"title\",\n    socialLoginInstructions: instruction\n  },\n};\n\nvar lock = new Auth0LockPasswordless(\n    CLIENT_ID,\n    DOMAIN,\n    options\n);\n\nlock.show()\n```\n\n### How to fix that?\nUpgrade to version `11.30.1`.\n\n### Will this update impact my users?\nThe fix uses [DOMPurify](https://github.com/cure53/DOMPurify) to sanitise the `flashMessage` and `languageDictionary` inputs. If you are including inline JavaScript in these fields, like `script` tags or `onclick` attributes, these will be removed.","status":"published","published":"2021-06-04T19:10:34Z","modified":"2023-02-01T05:05:58Z","cvss":[{"version":"3.1","score":8.1,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:36:36.66596Z"}],"nvd":[{"id":"CVE-2021-32641","description":"auth0-lock is Auth0's signin solution. Versions of nauth0-lock before and including `11.30.0` are vulnerable to reflected XSS. An attacker can execute arbitrary code when the library's `flashMessage` feature is utilized and user input or data from URL parameters is incorporated into the `flashMessage` or the library's `languageDictionary` feature is utilized and user input or data from URL parameters is incorporated into the `languageDictionary`. The vulnerability is patched in version 11.30.1.","status":"published","published":"2021-06-04T21:15:07.573Z","modified":"2026-06-17T03:53:19.857Z","cvss":[{"version":"3.1","score":8.1,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/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"},{"version":"2.0","score":4.3,"vector":"AV:N/AC:M/Au:N/C:N/I:P/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:06:54.439974Z"}],"osv":[{"id":"CVE-2021-32641","description":"auth0-lock is Auth0's signin solution. Versions of nauth0-lock before and including `11.30.0` are vulnerable to reflected XSS. An attacker can execute arbitrary code when the library's `flashMessage` feature is utilized and user input or data from URL parameters is incorporated into the `flashMessage` or the library's `languageDictionary` feature is utilized and user input or data from URL parameters is incorporated into the `languageDictionary`. The vulnerability is patched in version 11.30.1.","status":"published","published":"2021-06-04T21:15:07.573Z","modified":"2026-10-20T10:53:45.138757377Z","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":"2026-11-02T15:44:19.793849Z"},{"id":"GHSA-jr3j-whm4-9wwm","title":"Reflected XSS when using flashMessages or languageDictionary","description":"### Overview\n\nVersions before and including `11.30.0` are vulnerable to reflected XSS.  An attacker can execute arbitrary code when the library's\n- `flashMessage` feature is utilized and user input or data from URL parameters is incorporated into the `flashMessage`.\n- `languageDictionary` feature is utilized and user input or data from URL parameters is incorporated into the `languageDictionary`.\n\n### Am I affected?\nYou are affected by this vulnerability if you are using `auth0-lock` version `11.30.0` or lower and all of the following conditions apply:\n\n- You are utilizing `flashMessage` feature.\n- User input or data from URL parameters is incorporated into the `flashMessage`.\n\nAn example of a vulnerable snippet where query parameters are used to populate the `text` property of a `flashMessage`.\n```js\nvar params = new URLSearchParams(location.search);\nvar errorMessage = params.get('error__message');\nvar showParams = {};\n\nif (!!errorMessage === true) {\n  showParams.flashMessage = {\n    type: 'error',\n    text: 'We were unable to log you in. ' + errorMessage,\n  };\n}\n\nlock.show(showParams);\n```\n\nOR\n\n- You are utilizing `languageDictionary` feature.\n- User input or data from URL parameters is used in `languageDictionary` properties.\n\nAn example of a vulnerable snippet where query parameters are used to populate the `socialLoginInstructions` property of a `languageDictionary`.\n```js\nvar params = new URLSearchParams(location.search);\nvar instruction = params.get('instruction');\n\nvar options = {\n  languageDictionary: {\n    emailInputPlaceholder: \"something@youremail.com\",\n    title: \"title\",\n    socialLoginInstructions: instruction\n  },\n};\n\nvar lock = new Auth0LockPasswordless(\n    CLIENT_ID,\n    DOMAIN,\n    options\n);\n\nlock.show()\n```\n\n### How to fix that?\nUpgrade to version `11.30.1`.\n\n### Will this update impact my users?\nThe fix uses [DOMPurify](https://github.com/cure53/DOMPurify) to sanitise the `flashMessage` and `languageDictionary` inputs. If you are including inline JavaScript in these fields, like `script` tags or `onclick` attributes, these will be removed.","status":"published","published":"2021-06-04T19:10:34Z","modified":"2026-07-08T06:00:58.295148741Z","cvss":[{"version":"3.1","score":8.1,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T15:46:50.687609Z"}]}}