Back to Feed
VulnerabilitiesJul 28, 2026

Critical Arista VeloCloud Orchestrator Vulnerability Exploited as Zero-Day

Critical Arista VeloCloud Orchestrator vulnerability exploited as zero-day.

Summary

Arista Networks has released patches for a critical OS command injection vulnerability (CVE-2026-16812) in its VeloCloud Orchestrator (VCO) platform, which has been exploited in the wild as a zero-day. The vulnerability, with a CVSS score of 10, allows remote attackers to access privileged internal functionality without authentication. CISA has added it to its KEV catalog, urging federal agencies to patch within three days.

Full text

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. More from Ionut Arghire Beelzebub Raises $3.4 Million for Hacker-Trapping PlatformHacked Public Wi-Fi Gateways Used to Harvest Corporate CredentialsDentaQuest Data Breach Potentially Impacts Over 23 Million PeopleStrongestLayer Raises $4.1 Million in Seed Funding ExtensionEndpoint Security Firm Glow Launches With $180M in Funding at $1.2B ValuationEmpirical Security Raises $25 Million in Series A FundingNew HollowGraph Malware Abuses Microsoft 365 Calendar for C&C CommunicationEstée Lauder Discloses Impact From Oracle EBS Zero-Day Hack Latest News Unpatched Fastjson Vulnerability Exploited in AttacksOrigin Energy Data Breach Affects 900,000 AustraliansFor Some, So-Called ‘Skynet Day’ Came too Close to Sci-Fi After a Rogue Agent Hacked Into a StartupNew GitHub, PyPI Policies Boost Supply Chain SecurityPTC Windchill Vulnerability Exploited in Ransomware CampaignMedusaHVNC Malware Uses Hidden Windows Desktops to Evade DetectionNvidia and Tech Giants Launch AI Security AllianceCoca-Cola Confirms Data Breach After Fairlife Ransomware Attack Trending Daily Briefing NewsletterSubscribe to the SecurityWeek Email Briefing to stay informed on the latest threats, trends, and technology, along with insightful columns from industry experts. Webinar: Closing the Exploitation Gap July 22, 2026 Join this live webinar as we explore why exploitation is outpacing remediation, where risk is growing fastest, and what security leaders can do to close the gap before attackers take advantage. Register Virtual Event: CodeSecCon 2026 August 19, 2026 CodeSecCon bridges the gap between dev and security. Discover best practices for secure coding, innovative risk-reduction tools, and safe AI integration to cultivate a true DevSecOps culture. Safely secure your apps! Register People on the MoveBarry Childe has joined data sciences tech company Datavault AI as Chief Information Security Officer.John DeSimone, the former CEO of Nightwing, has been named Chief Operating Officer at Everfox.Sectigo has appointed Prem Hareesh as Corporate Chief Technology Officer.More People On The MoveExpert Insights Is Patching Dead? Vulnerability Management in the Post-Mythos Era You cannot out-patch a machine that writes a working exploit from a vulnerability description in twenty hours. Stop trying to optimize a game you cannot win. (Danelle Au) When Identity Verification Fails: Lessons from a Real-World SIM Swap and Near Account Takeover Identity confidence changes throughout every interaction and should be reassessed continuously as new risk signals emerge. (Torsten George) Legacy Systems, Real-World Impacts: The Reality of OT Security Legacy systems, safety concerns, and critical infrastructure risks make OT vulnerability disclosure one of cybersecurity's most challenging balancing acts. (Tod Beardsley) The Shift Toward Business-Aligned Risk Management Moving from isolated, technical data to a continuous risk lifecycle can help organizations align security controls with actual business consequences. (Steve Durbin) How to Conduct a Successful Audit of AI-Driven Software Development As AI-generated code becomes commonplace, CISOs need new audit strategies to measure developer practices, govern AI tool usage, and identify software risks before they reach production. (Matias Madou) Flipboard Reddit Whatsapp Whatsapp Email

Indicators of Compromise

  • cve — CVE-2026-16812
  • cve — CVE-2025-68686
  • cve — CVE-2022-42475
  • cve — CVE-2023-27997
  • cve — CVE-2024-21762

Entities

VeloCloud Orchestrator (product)Arista Networks (vendor)VeloCloud Orchestrator On-Prem (product)Broadcom (vendor)FortiOS (product)Fortinet (vendor)