{"id":"CVE-2023-54391","title":"Proxmox Virtual Environment (VE) 7.0 through 8.0 contains an authentication bypass vulnerability in libpve-access-control before 8.0.4 that allows unauthenticated attackers to authenticate as any existing enabled user without a configure…","summary":"Proxmox Virtual Environment (VE) 7.0 through 8.0 contains an authentication bypass vulnerability in libpve-access-control before 8.0.4 that allows unauthenticated attackers to authenticate as any existing enabled user without a configure…","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-304"],"published":"2026-09-01","updated":"2026-09-08","sourceUpdated":"2026-09-08T20:18:59.270","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2023-54391","references":[{"url":"https://forum.proxmox.com/threads/proxmox-virtual-environment-security-advisories.149331/page-4#post-867929","label":"disclosure@vulncheck.com"},{"url":"https://git.proxmox.com/?p=pve-access-control.git;a=commit;h=032e7d6d441f89a48cadfd7f47e957c8a561c022","label":"disclosure@vulncheck.com"},{"url":"https://git.proxmox.com/?p=pve-access-control.git;a=commit;h=032e7d6d441f89a48cadfd7f47e957c8a561c022","label":"disclosure@vulncheck.com"},{"url":"https://git.proxmox.com/?p=pve-access-control.git;a=commit;h=032e7d6d441f89a48cadfd7f47e957c8a561c022","label":"disclosure@vulncheck.com"},{"url":"https://git.proxmox.com/?p=pve-access-control.git;a=commit;h=032e7d6d441f89a48cadfd7f47e957c8a561c022","label":"disclosure@vulncheck.com"},{"url":"https://git.proxmox.com/?p=pve-access-control.git;a=commit;h=0f3d14d6be4d9f23e511701696a529ef3b7ffd61","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/proxmox-ve-authentication-bypass-via-tfa-challenge-parameter","label":"disclosure@vulncheck.com"}],"tags":["nvd","exploit-available","cve.org"],"epss":0.03023,"epssPercentile":0.87387,"exploits":{"github":3,"githubRepos":["https://github.com/disqualifier/psa-2026-00043-recovery","https://github.com/alexand0www/CVE-2023-54391-RCE","https://github.com/Lewis1766/CVE-2023-54391-POC"],"nuclei":["CVE-2023-54391"],"checkedAt":"2026-10-27T16:50:22.632Z"},"exploitAvailable":true,"ingestedAt":"2026-09-08T21:11:12.289Z","vendor":"Proxmox Server Solutions GmbH","product":"Proxmox Virtual Environment (VE)","affected":["proxmox_virtual_environment_ve >= 7.0 <= 7.4","proxmox_virtual_environment_ve 8.0"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"total","timestamp":"2026-09-02T11:55:35.310993Z"},"slug":"CVE-2023-54391","body":"## Overview\n\nProxmox Virtual Environment (VE) 7.0 through 8.0 contains an authentication bypass vulnerability in libpve-access-control before 8.0.4 that allows unauthenticated attackers to authenticate as any existing enabled user without a configured second factor by supplying an arbitrary tfa-challenge value in the API login endpoint. Attackers can send a POST request to the access ticket API endpoint with any value in the tfa-challenge parameter to completely skip password verification, gaining unauthorized access including to the root@pam account. All affected releases are end of life.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"abyssal","depthScore":67,"depthScoreParts":{"impact":53.9,"likelihood":0.6,"exploitation":12,"ransomware":0},"changes":[]}