CVE-2026-51082: A race condition between the vncproxy and vncwebsocket API calls in Proxmox Virtual Environment (PVE) 9.x pve-manager before 9.1.9 and 8.x before 8.4.19; qemu-server 9.x before 9.1

highCVSS 7.2CVE-2026-51082

A race condition between the vncproxy and vncwebsocket API calls in Proxmox Virtual Environment (PVE) 9.x pve-manager before 9.1.9 and 8.x before 8.4.19; qemu-server 9.x before 9.1.7 and 8.x before 8.4.7; and pve-container before 6.1.3 (PVE 9.x) and before 5.3.4 (PVE 8.x) allows an attacker with privileges to call "vncproxy" to hijack a VNC session that is established in parallel by a different user for a different VM.

Details

Source: NVD Recent CVEs (US · database · site)
Severity: high — CVSS 7.2
Published: 2026-07-17
Last updated: 2026-07-17
Exploitation: Not in CISA KEV at last sync

Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-51082

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-510820.22% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 13% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-51082	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

medium[UPDATE] [medium] Proxmox Virtual Environment: Multiple vulnerabilitiescert-bund
medium[NEW] [medium] Proxmox Virtual Environment: Multiple vulnerabilitiescert-bund

Recent advisories for A race condition

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

mediumCVE-2026-67607: LightFTP 2.3.1 contains a race condition vulnerability that allows remote attackers to crash t…nvd · 2026-07-31
unknownCVE-2026-16727: Concurrent Execution using Shared Resource with Improper Synchronization (“Race Condition”) in…nvd · 2026-07-30
criticalCVE-2026-64720: A race condition was addressed with improved state handling. This issue is fixed in iOS 26.6 a…nvd · 2026-07-27
mediumCVE-2026-43811: A race condition was addressed with improved checks. This issue is fixed in iOS 26.6 and iPadO…nvd · 2026-07-27
criticalCVE-2026-43805: A race condition was addressed with improved state handling. This issue is fixed in iOS 26.6 a…nvd · 2026-07-27
mediumCVE-2026-43781: A race condition was addressed with improved state handling. This issue is fixed in macOS Sequ…nvd · 2026-07-27