What is the CVSS score of CVE-2025-57539?

CVE-2025-57539 has a CVSS 3.1 base score of 5.4 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N. EPSS exploitation probability: 0.0%.

Which versions of Proxmox are affected by CVE-2025-57539?

CVE-2025-57539 presents moderate security risk, a cross-site scripting vulnerability rated CVSS 5.4. Attackers could inject scripts to steal sessions or perform actions as authenticated users.

Is there a public PoC exploit available for CVE-2025-57539?

Yes, a public proof-of-concept exploit is available for CVE-2025-57539. Prioritise patching immediately. EPSS: 0.0%.

How to fix or mitigate CVE-2025-57539?

Within 30 days: Identify affected systems and apply vendor patches as part of regular patch cycle. Verify Content-Security-Policy and output encoding.

Proxmox CVE-2025-57539

MEDIUM

Cross-site Scripting (XSS) (CWE-79)

2025-09-09 cve@mitre.org

XSS Proxmox Virtual Environment

5.4

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

5.4 MEDIUM

AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Lifecycle Timeline

Analysis Generated

Mar 28, 2026 - 19:11 vuln.today

PoC Detected

Sep 18, 2025 - 17:41 vuln.today

Public exploit code

CVE Published

Sep 09, 2025 - 17:16 nvd

MEDIUM 5.4

DescriptionCVE.org

A stored cross-site scripting (XSS) vulnerability in the U2F Origin field of the Datacenter configuration in Proxmox Virtual Environment (PVE) 8.4 allows authenticated users to store malicious input. The payload is rendered unsafely in the Web UI and executed when viewed by other users, potentially leading to session hijacking or other attacks.

AnalysisAI

A stored cross-site scripting (XSS) vulnerability in the U2F Origin field of the Datacenter configuration in Proxmox Virtual Environment (PVE) 8.4 allows authenticated users to store malicious input. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.

Technical ContextAI

This vulnerability is classified as Cross-Site Scripting (XSS) (CWE-79), which allows attackers to inject malicious scripts into web pages viewed by other users. A stored cross-site scripting (XSS) vulnerability in the U2F Origin field of the Datacenter configuration in Proxmox Virtual Environment (PVE) 8.4 allows authenticated users to store malicious input. The payload is rendered unsafely in the Web UI and executed when viewed by other users, potentially leading to session hijacking or other attacks. Affected products include: Proxmox Virtual Environment.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Sanitize all user input, use Content-Security-Policy headers, encode output contextually (HTML, JS, URL). Use frameworks with built-in XSS protection.