Arista VeloCloud Orchestrator On-Prem OS Command Injection
CVE-2026-16812 is a critical-severity improper neutralization of special elements used in an OS command vulnerability in VeloCloud Orchestrator On-Prem from Arista Networks, with a CVSS 3.1 base score of 10.0 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 5.2.3.14, 6.1.3.4, 6.4.2.4 as the first without the flaw, so updating VeloCloud Orchestrator On-Prem to one of those releases or later removes the exposure. CISA added it to the Known Exploited Vulnerabilities catalogue on July 27, 2026, which means attacks have been observed in the wild.
Attackers are already exploiting this vulnerability, according to CISA.
What to do
- Update VeloCloud Orchestrator On-Prem to 5.2.3.14 or 6.1.3.4 or 6.4.2.4 or 7.0.0.1, whichever matches your release line, or a later version.
- Update Velocloud Orchestrator to 5.2.3.14 or 6.1.3.4 or 6.4.2.4, whichever matches your release line, or a later version.
- CISA's 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.
- Read the advisory on arista.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Arista Networks | VeloCloud Orchestrator On-Prem | 5.2.0 up to, but not including, 5.2.3.14; 6.1.0 up to, but not including, 6.1.3.4; 6.4.0 up to, but not including, 6.4.2.4; 7.0.0 up to, but not including, 7.0.0.1 | 5.2.3.14, 6.1.3.4, 6.4.2.4, 7.0.0.1 |
| Arista | Velocloud Orchestrator | 5.2.0 up to, but not including, 5.2.3.14; 6.1.0 up to, but not including, 6.1.3.4; 6.4.0 up to, but not including, 6.4.2.4; 7.0.0 | 5.2.3.14, 6.1.3.4, 6.4.2.4 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H. Scored by CNA (arista.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 10.0 | Critical | CNA (arista.com) |
| CVSS 3.1 | 10.0 | Critical | CNA (arista.com) |
Official description
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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Special Elements used in an OS Command
The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command before it is sent to a downstream component.
How developers prevent this class of flaw
- If at all possible, use library calls rather than external processes to recreate the desired functionality.
- For any data that will be used to generate a command to be executed, keep as much of that data out of external control as possible. For example, in web applications, this may require storing the data locally in the session's state instead of sending it out to the client in a hidden form field.
- For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
More Improper Neutralization of Special Elements used in an OS Command vulnerabilities (CWE-78)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: active, automatable: yes, technical impact: total).
- Added to CISA's Known Exploited Vulnerabilities catalogue.
- Deadline for US federal agencies to remediate, set by CISA.
- Record last changed materially (score, affected products, status or references).
References
Advisories
Third-party and government advisories
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-16812US Government Resource
Other vulnerabilities in VeloCloud Orchestrator On-Prem
- 8.5 High severity
- 9.1 Critical severity
Recent Improper Neutralization of Special Elements used in an OS Command vulnerabilities
- 8.8 High severity
- 8.8 High severity
- 9.9 Critical severity
- 7.8 High severity
- 8.5 High severity
- 8.4 High severity
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