{"id":"CVE-2026-61628","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-61628","generatedAt":"2026-10-28T04:14:41.255Z","title":"Because the handler uses a check-then-act (TOCTOU) pattern between the \"onboarding already completed?\" check and the user-creation write, with no atomic guard, a remote unauthenticated attacker who can reach an instance in its pre-onboarding state can…","description":"nginx ignition is a user interface for the nginx web server. Prior to version 2.41.1, `POST /api/users/onboarding/finish` is registered as anonymous (unauthenticated) and creates a user with full ReadWrite admin permissions. Because the handler uses a check-then-act (TOCTOU) pattern between the \"onboarding already completed?\" check and the user-creation write, with no atomic guard, a remote unauthenticated attacker who can reach an instance in its pre-onboarding state can create an administrator account for themselves — and concurrent requests can create multiple admin accounts in a single race. Version 2.41.1 patches the issue.","published":"2026-09-21T15:17:30.000Z","lastModified":"2026-09-23T18:25:01.000Z","status":"Awaiting Analysis","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":8.1,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-362"],"affected":[],"epss":{"score":0.00434,"percentile":0.37544,"date":"2026-10-27","history":[{"date":"2026-09-22","score":0.00357,"percentile":0.29456}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.43%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[{"kind":"new","label":"New CVE","at":"2026-09-21T15:17:30.000Z","detail":{"score":"8.1","severity":"HIGH","publishedAt":"2026-09-21T15:17:30.290Z"},"summary":"New CVE, high severity (CVSS 8.1)."}],"references":[{"url":"https://github.com/lucasdillmann/nginx-ignition/commit/0586b4e55ab780676d3553a2592979dfa2fb0183","source":"security-advisories@github.com"},{"url":"https://github.com/lucasdillmann/nginx-ignition/security/advisories/GHSA-pxcx-fv34-x9p5","source":"security-advisories@github.com"},{"url":"https://github.com/lucasdillmann/nginx-ignition/security/advisories/GHSA-pxcx-fv34-x9p5","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-61628","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}