CVE-2022-39197 Fortra Cobalt Strike Teamserver Cross-Site Scripting (XSS) Vulnerability
Fortra Cobalt Strike contains a cross-site scripting (XSS) vulnerability in Teamserver that would allow an attacker to set a malformed username in the Beacon configuration, allowing them to execute code remotely.
From the CISA KEV catalogue version 2026.11.06, with Cybergen analysis. Updated 6 Nov 2026.
Should You Worry?
- CISA confirmed exploitation in the wild and added it to the Known Exploited Vulnerabilities catalogue on 30 Mar 2023.
- Rated Medium severity (CVSS 6.1, scored by CISA).
- It has been in the catalogue for 1,317 days. Systems still unpatched now have almost certainly been scanned for it.
What It Is
An XSS (Cross Site Scripting) vulnerability was found in HelpSystems Cobalt Strike through 4.7 that allowed a remote attacker to execute HTML on the Cobalt Strike teamserver. To exploit the vulnerability, one must first inspect a Cobalt Strike payload, and then modify the username field in the payload (or create a new payload with the extracted information and then modify that username field to be malformed).
What To Do Now
- 1
Find it
Search your asset inventory and external attack surface for Fortra Cobalt Strike. Include cloud images, appliances and anything a supplier runs for you.
Attack Surface Management - 2
- 3
Hunt for compromise
If an affected system was reachable before you patched, assume it may have been hit. Check logs, new accounts, web shells and outbound connections from the date of exposure.
Incident Response - 4
Prove it is fixed
Rescan or test the system after patching. Upgrades that fail silently and forgotten secondary instances are common.
Penetration Testing
The Compliance Clock
General guidance, not legal advice. Your obligations depend on your sector, scope and jurisdiction.
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