Known exploited · Fortra

CVE-2022-39197: Fortra Cobalt Strike Teamserver Cross-Site Scripting (XSS) Vulnerability

What it is

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.

Added March 30, 2023Due April 20, 2023CISA KEV catalog 2026.10.01

Vendor: Fortra
Product: Cobalt Strike
Added to KEV: March 30, 2023
CISA due date: April 20, 2023
Ransomware use: Unknown
Weakness: CWE-20: Improper Input Validation, CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

What CISA requires

Apply updates per vendor instructions.

Forensic triage

What to do now

Find every instance of Cobalt Strike you run, including the forgotten ones, and check its version against the vendor advisory.
Apply the vendor's fix or mitigation, before April 20, 2023 if you are bound by CISA's deadline, sooner if it faces the internet.
Assume it was tried against you already: look for signs of exploitation from the date it was added, not from the day you patched.
Until every instance is patched, block the attack at the edge: a WAF in blocking mode stops cross-site scripting payloads.

References

CVE-2022-39197 in the National Vulnerability Database

The Dome

Block it at the edge while you patch

The Dome's WAF runs the OWASP Core Rule Set in blocking mode and stops cross-site scripting payloads before they reach your application.

See the Dome

T Academy

Train the engineers who fix it

Security engineering on real hosts in the browser, every objective checked on the machine. The first two lessons of Linux 1 are free.

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Source: CISA Known Exploited Vulnerabilities Catalog (public domain), catalog version 2026.10.01.