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Critical · 9.8 Scanner template Public exploit CVE-2023-54391 EUVD-2023-60613GHSA-m457-grcf-698x

Proxmox VE 7.0-8.0 Authentication Bypass via tfa-challenge Parameter

Published Sep 1, 2026 · Updated Oct 1, 2026 · Assigned by VulnCheck

Vendor: Proxmox Server Solutions Product: Proxmox Virtual Environment (VE) Category: Virtualization

Description

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.

Affected products

VendorProductAffectedFixed
Proxmox Server Solutions Proxmox Virtual Environment (VE) 7.0 – ≤ 7.4, 8.0 —

Public exploits

Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.

Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.

GitHub 3 repositories

Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.

Automated scanner template

A ready-made Nuclei template detects this vulnerability automatically. Vulnerabilities with public scanner templates are typically probed across the internet soon after the template appears — exposed systems should be patched first.

Source: projectdiscovery/nuclei-templates (MIT) — updated daily. Only links are listed.

Advisories 1

References