CVE-2023-54391Proxmox VE 7.0-8.0 Authentication Bypass via tfa-challenge Parameter
Updated under an hour ago ()
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It affects Proxmox Server Solutions GmbH Proxmox Virtual Environment (VE). Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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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 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.
- CVSS
- 9.8 CRITICAL (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- CWE-304
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- VulnCheck
- NVD analysis
- Deferred
- Record last updated
- Oct 1, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Proxmox Server Solutions GmbH Proxmox Virtual Environment (VE) proxmox_server_solutions:proxmox_virtual_environment_ve (from the name) | from 7.0 through 7.4; 8.0 | CNA record |
References
- https://forum.proxmox.com/threads/proxmox-virtual-environment-security-advisories.149331/page-4#post-867929vendor-advisory
- https://git.proxmox.com/?p=pve-access-control.git;a=commit;h=032e7d6d441f89a48cadfd7f47e957c8a561c022patch
- https://git.proxmox.com/?p=pve-access-control.git;a=commit;h=0f3d14d6be4d9f23e511701696a529ef3b7ffd61
- https://www.vulncheck.com/advisories/proxmox-ve-authentication-bypass-via-tfa-challenge-parameterthird-party-advisory
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.