Microsoft Exchange Server Privilege Escalation Vulnerability
Microsoft / Exchange Server
A privilege escalation vulnerability exists in Microsoft Exchange Server. An attacker who successfully exploited this vulnerability could attempt to impersonate any other user of the Exchange server.
- CVE identifier
- CVE-2018-8581
- Added to KEV
- Mar 3, 2022
- CISA catalog dueDate
- Mar 17, 2022
The dates above are catalog fields. The addition date does not establish when the vulnerability was discovered or first exploited. Confirm which requirements apply to your organisation separately.
Publisher's required action
Apply updates per vendor instructions.
This wording is attributed to the CISA snapshot. Verify current vendor guidance, affected versions and your deployment before applying changes.
Keep the signals separate.
- Ransomware use, as reported by CISA
- Known
- CVSS severity
- Not supplied by KEV
- EPSS probability
- 27.36%
EPSS score date: 2026-09-27T12:00:21Z. Percentile: 98.00%. Model version: v2026.06.15.
A dated estimate of exploitation probability over the following 30 days, not a severity score or a probability of a breach in your environment.
Inspect the EPSS source ↗“Unknown” ransomware use is an unknown source field, not proof that ransomware activity has not occurred.
Source notes
https://nvd.nist.gov/vuln/detail/CVE-2018-8581
Source & freshness
Source updated: Sep 27, 2026, 9:30 PM UTC
Successfully checked: Sep 27, 2026, 11:50 PM UTC
This snapshot is older than 36 hours. Check current publisher guidance.
Automated source record, not an editorial advisory or an independent discovery. No affected or fixed version is inferred, and no organisation-specific risk rating is generated.