CVE-2023-54391

criticalpriority · attend · 50EPSS 0.030 · 87 %ileexploit · PoCDE

grimoire priorityP1 · Urgent

Exploitable?

Public exploit

3 exploits · PoC

Likely / severe?

3.02% (87th) EPSS

CVSS 9.8 · critical

Is it mine?

3 products

Check your exposure

Who says so?

1 sources

cert_bund

EPSS · scored 2026-10-27

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

Technical severity, 0–10. One row per scoring source.

9.8

010

base score 0–10 · higher = more severe · hover a vector to decode

v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hprimary · disclosure@vulncheck.comexploitability 3.9 · impact 5.9

v4.09.3criticalCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Xsecondary · disclosure@vulncheck.com

v4.09.3criticalCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:A/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Xsecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: yes · Technical Impact: totalcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-304US

exploits (3)

Public proof-of-concept and weaponised exploit code.

Lewis1766/CVE-2023-54391-POCLewis1766/CVE-2023-54391-POCPoC · poc_in_github
alexand0www/CVE-2023-54391-RCECVE-2023-54391: Proxmox VE Authentication Bypass RCE ExploitPoC · poc_in_github
disqualifier/psa-2026-00043-recoveryRecovery notes for proxmox advisory ID: PSA-2026-00043-1 (CVE-2023-54391)PoC · poc_in_github

affected products (3)

Products and version ranges known to be affected.

Proxmox Virtual Environment 7.0-7.4all versionscert_bundDEcpe:/a:proxmox:virtual_environment:7.4
Proxmox Virtual Environment libpve-access-control <8.0.4all versionscert_bundDE
Proxmox Virtual Environment≤ libpve-access-control <8.0.4cert_bundDE

advisories (1)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2026-3144Proxmox Virtual Environment: Schwachstelle ermöglicht Erlangen von AdministratorrechtenDeutsch2026-09-01csaf · cert_bundDE
Ein entfernter, anonymer Angreifer kann eine Schwachstelle in Proxmox Virtual Environment ausnutzen, um Administratorrechte zu erlangen.

sources

Which sources assert this record, and when.

cert_bund NVD CVE.org MITRE

published 2026-09-01modified 2026-09-08

references (4) nvd

External citations — patches, advisories, analysis.

scry

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