Microsoft Office Memory Corruption Vulnerability
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.
- Vendor
- Microsoft
- Product
- Office
- CVSS
- 8.8
- EPSS (exploit probability)
- 95.1%
- Status
- kev
- CISA patch-by (BOD 22-01)
- Added to KEV
Is CVE-2018-0798 being exploited?
Yes. CISA added CVE-2018-0798 to its Known Exploited Vulnerabilities catalog on . CISA only lists a CVE when it has reliable evidence of exploitation in the wild.
FIRST's EPSS model puts the probability of exploitation activity in the next 30 days at 95.1% (scored October 14, 2026).
- CISA KEV[ LISTED ]
- ENISA EUVD (exploited)[ — ]
- CIRCL KEV[ — ]
Catalog snapshot 2026-11-13. Full cross-catalog view: /kev-comparison
CVE-2018-0798 timeline
Every event links to its source. Catalog dates are each catalog's own; day offsets count from NVD publication. Data: JSON
What to do
CISA required actionApply updates per vendor instructions.
US federal civilian agencies must remediate by (181 days after listing) under BOD 22-01. Everyone else: that deadline is a sensible upper bound, not a target. Vendor guidance and the NVD record are linked under Source above.
Other Microsoft Office CVEs we track
| CVE / Vulnerability | Severity | CVSS | EPSS | Added to KEV |
|---|---|---|---|---|
| CVE-2026-124194 Microsoft Office Outlook Missing User Interaction for Potentially Unsafe Action Vulnerability | [ MEDIUM ] | 6.5 | 1.6% | |
| CVE-2009-0238 Microsoft Office Remote Code Execution | [ HIGH ] | 8.8 | 42.9% | |
| CVE-2026-21514 Microsoft Office Word Reliance on Untrusted Inputs in a Security Decision Vulnerability | [ HIGH ] | 7.8 | 1.6% | |
| CVE-2026-21509 Microsoft Office Security Feature Bypass Vulnerability | [ HIGH ] | 7.8 | 70.8% | |
| CVE-2009-0556 Microsoft Office PowerPoint Code Injection Vulnerability | [ HIGH ] | 8.8 | 67.3% | |
| CVE-2007-0671 Microsoft Office Excel Remote Code Execution Vulnerability | [ HIGH ] | 8.8 | 44.1% | |
| CVE-2023-23397 Microsoft Office Outlook Privilege Escalation Vulnerability | [ CRITICAL ] | 9.8 | 97.2% | |
| CVE-2023-21715 Microsoft Office Publisher Security Feature Bypass Vulnerability | [ HIGH ] | 7.3 | 12.0% |