CVE-2026-16812: Arista VeloCloud Orchestrator On-Prem OS Command Injection Vulnerability

Should you act?

Exploited: patch now if you run it

CISA has confirmed exploitation in the wild. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• Yes, if you run Arista VeloCloud Orchestrator. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2026-07-27, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2026-07-30; treat that as the outer limit, not the target.
• EPSS 1.0%, percentile 62: FIRST’s model estimates a 1.0% chance of exploitation activity in the next 30 days, higher than 62% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
• Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
• Editorial verdict: Act now. Arista VeloCloud Orchestrator: Two Exploited CVSS 10 Flaws — On-prem VCO operators should move to 5.2.3.16 or 6.4.2.8 now, lock the web interface down and hunt for the published backdoor files; both flaws are exploited, and the July fixes do not cover the September bug.

What it is

VeloCloud Orchestrator (VCO) on-prem has a security issue where this issue may allow a remote attacker to access privileged internal functionality and impact the VCO host. Successful exploitation may compromise the confidentiality, integrity, and availability of the orchestrator and data managed by the orchestrator. This functionality was intended to be for internal use only and is not intended to be remotely accessible. Hosted and Dedicated versions of VCO have already been patched in advance of this notice going out. This issue was discovered externally and is known to be actively exploited.

CISA’s summary

Arista VeloCloud Orchestrator On-Prem contains an OS command injection vulnerability that may allow a remote attacker to access privileged internal functionality and impact the VCO host. Successful exploitation may compromise the confidentiality, integrity, and availability of the orchestrator and data managed by the orchestrator.

Weakness type: CWE-78.

Product: Arista VeloCloud Orchestrator · Assigned by: Arista · Published: 2026-07-27

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Attack requirements: none
• Privileges required: none (no login)
• User interaction: none

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: added 2026-07-27; federal due date 2026-07-30. Known ransomware use: Unknown.
• CISA required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
• CISA SSVC assessment: exploitation active, automatable yes, technical impact total.
• FIRST EPSS (model of 2026-10-21): 1.00% probability of exploitation activity in the next 30 days; percentile 62.

Timeline

• 2026-07-27 — Added to CISA’s Known Exploited Vulnerabilities catalog
• 2026-07-27 — CVE record published by Arista
• 2026-07-27 — erroneo.us brief: Arista VeloCloud Orchestrator: Two Exploited CVSS 10 Flaws
• 2026-07-28 — CVE record last updated
• 2026-07-30 — CISA remediation deadline for US federal agencies

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vendor and project advisories, patches

1. Security Advisory 0144 arista.com

Vulnerability records

1. CVE.org record CVE-2026-16812 cve.org
2. NVD entry CVE-2026-16812 nvd.nist.gov

Government

1. CISA Known Exploited Vulnerabilities catalog entry cisa.gov
2. Listed in CISA KEV notes (cisa.gov) cisa.gov
3. Listed in CISA KEV notes (cisa.gov) cisa.gov

All exploited Arista vulnerabilities · Today’s Security Digest