vCenter Flaw Exploited Just Five Days After Disclosure

CVE-2026-59310 is a directory traversal (CWE-22) vulnerability in the Syslog server component of VMware vCenter Server, rated critical at CVSS 9.8. It can be triggered over the network without authentication or user interaction, allowing a malicious actor with network access to vCenter to achieve arbitrary code execution. An attacker who exploits it gains code execution on the vCenter appliance, and reported campaigns show it has been used to establish persistent remote access and, by a suspected China-nexus actor, to deploy Babuk ransomware. Any organization running an affected version of vCenter Server is exposed, especially where the management interface is reachable from the internet; the available data does not specify affected version ranges. Exploitation is confirmed in the wild: CISA added the flaw to its Known Exploited Vulnerabilities catalog on 2026-08-18, it was reportedly exploited just five days after disclosure, and EPSS estimates a 45.9% probability of exploitation within 30 days (99th percentile).

Do: Upgrade vCenter Server to the patched release identified in Broadcom's advisory (no specific version ranges are provided in this data) and prioritize any vCenter that is internet-facing, in line with CISA KEV and BOD 26-04 requirements for federal agencies. Until patched, restrict access to the vCenter management interface to trusted networks and verify whether the vCenter Syslog server is enabled. Hunt for compromise indicators, including unexplained remote-access persistence and Babuk ransomware artifacts, given the documented China-nexus exploitation.