Unauthenticated bypass lets attackers log in as any user including root on a widely deployed virtualization platform; can lead to full infrastructure compromise and is high-impact.
CVE-2023-54391
Unauthenticated Proxmox VE auth bypass allows login as any user, including root.
Is CVE-2023-54391 being exploited?
Not confirmed. CVE-2023-54391 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 1.7% probability of exploitation in the next 30 days.
How severe is CVE-2023-54391?
CVE-2023-54391 is rated Critical with a CVSS score of 9.3. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2023-54391?
Yes. A fix has been recorded for CVE-2023-54391. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2023-54391 affect?
CVE-2023-54391 affects Proxmox VE 7.0 through 8.0, libpve-access-control before 8.0.4, Proxmox API /access/ticket endpoint. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2023-54391?
Upgrade to libpve-access-control 8.0.4/Proxmox patched release; restrict/block management API access until patched.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Unauthenticated API auth bypass via tfa-challenge grants full account takeover (including root@pam), enabling admin control, VM access, and lateral movement.
Immediate action required
- affected>= 7.0 and <= 7.4
- affected8.0
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.