High [CVE-2026-51082] 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
This high-severity Proxmox advisory covers CVE-2026-51082 affecting Proxmox Virtual Environment, Proxmox.
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Summary
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.
- before 9.1.9
- before 8.4.19
- before 9.1.7
- before 8.4.7
- before 6.1.3
- before 5.3.4
Official advisory · high-confidence parse· fetched 2 months ago·verify at source
- 9.1.9
- 8.4.19
- 9.1.7
- 8.4.7
- 6.1.3
- 5.3.4
Official advisory · high-confidence parse· fetched 2 months ago·verify at source
Mitigation
Upgrade to a fixed release: 9.1.9, 8.4.19, 9.1.7, 8.4.7, 6.1.3, 5.3.4. That is the remediation for this advisory.
The vendor advisory may list additional interim mitigations or workarounds not captured here — review it before change work.
Official advisory · high-confidence parse· fetched 2 months ago·verify at source
Discussion(0)
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