CVE-2023-54391
CVSS v3
9.8
CRITICAL
EPSS Score
3.0 %
exploit probability, as of 2026-09-25
CISA KEV
No
known exploited
Exploitation
—
SSVC status
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 unauthoriz
Technical details
- Published
- 2026-09-01
- Last Modified
- 2026-09-03
Frequently asked questions
What is CVE-2023-54391?
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 unauthoriz
Is CVE-2023-54391 actively exploited?
Active exploitation of CVE-2023-54391 has not been confirmed. Its EPSS score was 3.0% on 2026-09-25, the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2023-54391?
CVE-2023-54391 has a CVSS v3 base score of 9.8 (CRITICAL severity).
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