CVE-2021-30116: in the CISA KEV catalogue
Kaseya Virtual System/Server Administrator (VSA) Information Disclosure Vulnerability. CISA added CVE-2021-30116 to the Known Exploited Vulnerabilities catalogue on 2021-11-03 with a default due date of 2021-11-17. Known ransomware campaign use: Known. Forensic triage flag: No.
Kaseya Virtual System/Server Administrator (VSA) contains an information disclosure vulnerability allowing an attacker to obtain the sessionId that can be used to execute further attacks against the system. (CISA description)
- Vendor / product
- Kaseya Virtual System/Server Administrator (VSA)
- CWE
- CWE-522
- CISA required action
- Apply updates per vendor instructions.
- EPSS
- 86%, percentile 99 (scored 2026-11-03)
EPSS puts about 86 in 100 odds (86%) on exploitation activity being observed in the next 30 days. Its score is higher than or equal to that of 99% of scored CVEs. This is a model estimate about exploitation anywhere, not about your environment.
Vendor and reference links (from CISA)
Your own deadline under CISA BOD 26-04 depends on exposure, automatability and technical impact: work it out with the BOD 26-04 calculator.
Frequently asked questions
Is CVE-2021-30116 in the CISA KEV catalogue?
Yes. CISA added CVE-2021-30116 (Kaseya Virtual System/Server Administrator (VSA) Information Disclosure Vulnerability) to the Known Exploited Vulnerabilities catalogue on 2021-11-03. CISA's default due date for it is 2021-11-17.
Is CVE-2021-30116 used in ransomware attacks?
CISA marks known ransomware campaign use as Known for CVE-2021-30116.
What should I do about CVE-2021-30116?
CISA's required action: Apply updates per vendor instructions.
Sources
- CISA, Known Exploited Vulnerabilities Catalog (accessed 2026-11-03)
- FIRST, Exploit Prediction Scoring System (EPSS) (EPSS by FIRST; scores generated by Empirical Security)
- NVD record for CVE-2021-30116