CVE-2026-76506 Cisco UCS: Authenticated RCE in web interface

CVE-2026-76506 affects Cisco UCS Central Software and stems from insufficient input validation in HTTP requests to the web-based management interface. The flaw allows an authenticated attacker to execute arbitrary code remotely, obtain sensitive information, write arbitrary files to the filesystem, and run unauthorized commands. Exploitation requires valid credentials on the affected device, limiting exposure to internal users or those with compromised accounts.

The CVSS score is 7.6, classified as High severity. The vulnerability was publicly disclosed on November 4, 2026, with concurrent software updates released by Cisco. There is no public evidence of active exploitation or verified exploits in the wild at this time. Social media signals show growing awareness among security teams with 5 posts in 24 hours related to the CVE, but no indication of ongoing attacks.

Defenders must first identify which versions of Cisco UCS Central Software are deployed in critical environments. For systems running version 2.1, apply the patch 2.1(2c) immediately. Systems on version 2.0 or earlier have no point patch and require strategic migration to a fixed version. In the interim, enforce strict access control to the UCS Central web interface, limiting it to trusted IP addresses and isolated administrative networks.

UCS Central is a critical component for managing Cisco UCS infrastructure in datacenters and cloud environments. Compromise of its administrative interface risks lateral movement across the entire virtualized infrastructure. While valid credentials are required, the vulnerability represents a privilege escalation vector for compromised accounts or insider threats. The patch must be treated as highest priority for any organization operating UCS Central.