CVE-2019-0803: in the CISA KEV catalogue
Microsoft Win32k Privilege Escalation Vulnerability. CISA added CVE-2019-0803 to the Known Exploited Vulnerabilities catalogue on 2021-11-03 with a default due date of 2022-05-03. Known ransomware campaign use: Known. Forensic triage flag: No.
Microsoft Win32k contains an unspecified vulnerability due to it failing to properly handle objects in memory causing privilege escalation. Successful exploitation allows an attacker to run code in kernel mode. (CISA description)
- Vendor / product
- Microsoft Win32k
- CWE
- Not listed
- CISA required action
- Apply updates per vendor instructions.
- EPSS
- 45%, percentile 98 (scored 2026-11-03)
EPSS puts about 45 in 100 odds (45%) on exploitation activity being observed in the next 30 days. Its score is higher than or equal to that of 98% 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-2019-0803 in the CISA KEV catalogue?
Yes. CISA added CVE-2019-0803 (Microsoft Win32k Privilege Escalation Vulnerability) to the Known Exploited Vulnerabilities catalogue on 2021-11-03. CISA's default due date for it is 2022-05-03.
Is CVE-2019-0803 used in ransomware attacks?
CISA marks known ransomware campaign use as Known for CVE-2019-0803.
What should I do about CVE-2019-0803?
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-2019-0803