CVE-2018-0798: in the CISA KEV catalogue
Microsoft Office Memory Corruption Vulnerability. CISA added CVE-2018-0798 to the Known Exploited Vulnerabilities catalogue on 2021-11-03 with a default due date of 2022-05-03. Known ransomware campaign use: Unknown. Forensic triage flag: No.
Microsoft Office contains a memory corruption vulnerability due to the way objects are handled in memory. Successful exploitation allows for remote code execution in the context of the current user. This vulnerability is known to be chained with CVE-2018-0802. (CISA description)
- Vendor / product
- Microsoft Office
- CWE
- CWE-787
- CISA required action
- Apply updates per vendor instructions.
- EPSS
- 95%, percentile 99 (scored 2026-11-03)
EPSS puts about 95 in 100 odds (95%) 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-2018-0798 in the CISA KEV catalogue?
Yes. CISA added CVE-2018-0798 (Microsoft Office Memory Corruption Vulnerability) to the Known Exploited Vulnerabilities catalogue on 2021-11-03. CISA's default due date for it is 2022-05-03.
Is CVE-2018-0798 used in ransomware attacks?
CISA marks known ransomware campaign use as Unknown for CVE-2018-0798. That means CISA lacks confirmation, not that ransomware groups do not use it.
What should I do about CVE-2018-0798?
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-2018-0798