Vulnerabilities Critical Arista VeloCloud Orchestrator Vulnerability Exploited as Zero-Day Impacting on-premises deployments, the OS command injection allows attackers to access privileged internal functionality. By Ionut Arghire | July 28, 2026 (2:40 AM ET) Flipboard Reddit Whatsapp Whatsapp Email Arista Networks on Monday released patches for a critical-severity OS injection vulnerability in the VeloCloud Orchestrator (VCO) centralized management platform, warning that it has been exploited in the wild as a zero-day. The security defect is tracked as CVE-2026-16812, has a maximum CVSS score of 10, and could be exploited remotely to access privileged functionality intended for internal use only. “Successful exploitation may compromise the confidentiality, integrity, and availability of the orchestrator and data managed by the orchestrator,” Arista Networks notes in its advisory . According to the company, only VeloCloud Orchestrator On-Prem (formerly VeloCloud Orchestrator by Broadcom) is affected by the bug. The flaw was addressed in VCO versions 5.2.3.14, 6.1.3.4, 6.4.2.4, and 7.0.0.1. “This issue was discovered externally and is known to be actively exploited,” Arista warned. The company also pointed out that no special configuration or authentication is required for successful exploitation. Advertisement. Scroll to continue reading. “VCO is exposed by default. There is no configuration that can prevent the exposure. A successful attack requires network access to the VCO web interface. VCO tenant or operator credentials are not required for this exposure,” Arista says. Defenders are advised to check VCO web access logs for unexpected activity and unusual URL-like path components, and to review VCO backend application logs and system logs for follow-up activity, including requests from malicious IPs, outbound HTTP/S activity, and privileged actions not associated with administrative workflows. They should also hunt for unexpected actions involving command execution, database exports, file creation, and access to device inventory, configurations, certificates, credentials, and key material. “If compromise is suspected, operators should preserve VCO web access logs, backend application logs, system logs, database logs, and relevant file-system timestamps before remediation where operationally feasible,” Arista notes. On Monday, the US cybersecurity agency CISA added CVE-2026-16812 to its Known Exploited Vulnerabilities (KEV) catalog, urging federal agencies to patch it within three days, as mandated by BOD 26-04. Additionally, CISA warns that hackers have been exploiting CVE-2025-68686, which Fortinet assigned earlier this year to a patch bypass of exploited FortiOS SSL-VPN vulnerabilities, including CVE-2022-42475 , CVE-2023-27997 , and CVE-2024-21762 . Related: PTC Windchill Vulnerability Exploited in Ransomware Campaign Related: New Check Point Zero-Day Vulnerability Exploited in the Wild Related: Flaw in Adobe Extension With 300M Installs Enabled WhatsApp Data Theft Related: Fourth SharePoint Vulnerability Exploited in Past Month’s Wave of Attacks Written By Ionut Arghire Ionut Arghire is an international correspondent for SecurityWeek. Daily Briefing Newsletter Subscribe to the SecurityWeek Email Briefing for the latest cybersecurity threats, trends, and expert insights. 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