How severe is CVE-2018-8581?

CVE-2018-8581 has a CVSS score of 7.4/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2018-8581?

Affected package information for CVE-2018-8581 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2018-8581?

No fixed version has been published for CVE-2018-8581 yet. Monitor the advisory for updates, apply mitigations recommended by the vendor, and use O3 Security to track when a fix becomes available in your stack.

Is CVE-2018-8581 actively exploited in the wild?

Yes. There are 9 known exploit references for CVE-2018-8581, including 6 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2018-8581?

CVE-2018-8581 has an EPSS (Exploit Prediction Scoring System) score of 91.8%, placing it in the 100th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

Is CVE-2018-8581 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2018-8581 (Microsoft Exchange Server Privilege Escalation Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2022-03-03. CISA required all US federal civilian agencies to remediate this vulnerability by 2022-03-17. The required action was: Apply updates per vendor instructions. This CVE has been used in known ransomware campaigns. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

Which products and versions are affected by CVE-2018-8581?

CVE-2018-8581 affects microsoft exchange server (4 versions, e.g. 2010, 2013, 2016…). Check the affected-products list on this page against your deployed version to confirm exposure.

When was CVE-2018-8581 published, and has it been updated?

CVE-2018-8581 was published on November 14, 2018 and was last updated on October 28, 2025. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CISA KEV·Added 2022-03-03 — agencies required to remediate by 2022-03-17 · Ransomware

CVE-2018-8581

HIGH

An elevation of privilege vulnerability exists in Microsoft Exchange Server, aka "Microsoft Exchange Server Elevation of Privilege Vulnerability." This affects Microsoft Exchange Server.

Published

Nov 14, 2018

Updated

Oct 28, 2025

Affected

0 pkgs

Patched

None yet

Exploits

9 known

EPSS Exploitation Probability

via FIRST.org ↗

91.8%probability of exploitation in next 30 days

Very High Risk100th percentile0.00%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Description

An elevation of privilege vulnerability exists in Microsoft Exchange Server, aka "Microsoft Exchange Server Elevation of Privilege Vulnerability." This affects Microsoft Exchange Server.

Affected Products

1 product · 4 configurations

Application

exchange servermicrosoft

4 versions

2010201320162019

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.