CVE-2026-20199Network attack vector

Root code execution via crafted certificate upload

Published May 20, 2026 · Updated May 20, 2026

Command injection in Cisco ThousandEyes Virtual Appliance before 0.262.0 allows remote authenticated users to execute code as root. The SSL certificate handler fails to neutralize elements in an uploaded certificate before downstream command processing. Valid administrative credentials and appliance-management access are required, after which arbitrary code runs on the underlying operating system as root.

CVSS severity4.7
Medium
EPSS probability0.44%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Command injection in Cisco ThousandEyes Virtual Appliance before 0.262.0 allows remote authenticated users to execute code as root. The SSL certificate handler fails to neutralize elements in an uploaded certificate before downstream command processing. Valid administrative credentials and appliance-management access are required, after which arbitrary code runs on the underlying operating system as root.

The record

CVE
CVE-2026-20199
Published
May 20, 2026
Updated
May 20, 2026
Vendor
ClamAV
Product
ThousandEyes Enterprise Agent
Classifications
CWE-74, T1059
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. May 20, 2026CVE publishedPublication date reported by the CVE source.
  2. May 20, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=N/A

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

ClamAV · ThousandEyes Enterprise Agentversion=N/A

Published CVSS scores

4.7Cisco Systems, Inc.CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L/E:X/RL:X/RC:X
7.2NIST NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-74Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
T1059Command and Scripting Interpreter

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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