How severe is CVE-2023-43320?

CVE-2023-43320 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2023-43320 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (58th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-43320?

CVE-2023-43320 primarily affects Proxmox Backup Server. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2023-43320?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2023-43320 published?

CVE-2023-43320 was published on 2023-09-27 and last updated on 2026-06-17.

CVE-2023-43320

CVE-2023-43320 is a high-severity vulnerability in Proxmox Backup Server with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: High (CVSS 3.x base score 8.8)
EPSS exploit prediction: 1% (58th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Proxmox Backup Server
Published: 2023-09-27
Last modified: 2026-06-17

Description

An issue in Proxmox Server Solutions GmbH Proxmox VE v.5.4 thru v.8.0, Proxmox Backup Server v.1.1 thru v.3.0, and Proxmox Mail Gateway v.7.1 thru v.8.0 allows a remote authenticated attacker to escalate privileges via bypassing the two-factor authentication component.

Frequently asked questions

What is CVE-2023-43320?: An issue in Proxmox Server Solutions GmbH Proxmox VE v.5.4 thru v.8.0, Proxmox Backup Server v.1.1 thru v.3.0, and Proxmox Mail Gateway v.7.1 thru v.8.0 allows a remote authenticated attacker to escalate privileges via bypassing the two-factor authentication component.
How severe is CVE-2023-43320?: CVE-2023-43320 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2023-43320 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (58th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-43320?: CVE-2023-43320 primarily affects Proxmox Backup Server. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-43320?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2023-43320 published?: CVE-2023-43320 was published on 2023-09-27 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:a:proxmox:backup_server:*:*:*:*:*:*:*:*
cpe:2.3:a:proxmox:proxmox_mail_gateway:*:*:*:*:*:*:*:*
cpe:2.3:a:proxmox:virtual_environment:*:*:*:*:*:*:*:*