Microsoft Enhanced Cryptographic Provider Privilege Escalation Vulnerability

What it is

Microsoft Enhanced Cryptographic Provider contains an unspecified vulnerability that allows for privilege escalation.

VulnCheck tracked exploitation 148 days before CISA's KEV listing. VulnCheck's broader catalog of in-the-wild exploitation evidence picked this up before it landed on CISA's formal list. Per-CVE fact about this entry; not a population claim about lead time in general.

Who's affected

Affects anyone running Microsoft Enhanced Cryptographic Provider. Microsoft products in a small practice typically sit close to credentials, email, or document workflows — treat the patch as in-scope.

What to do

Apply updates per vendor instructions.

If you don't have someone in-house to verify the patch deployed across every endpoint — or you're not sure whether you're affected — that's exactly the kind of triage we do. Book a free 20-minute triage call.

Microsoft fix

• KB5003646 (Security Update)
• KB5003635 (Security Update)
• KB5003637 (Security Update)
• KB5003687 (Security Update)
• KB5003638 (Security Update)
• KB5003667 (Monthly Rollup)
• KB5003694 (Security Only)
• KB5003671 (Monthly Rollup)
• KB5003681 (Security Only)
• KB5003661 (Monthly Rollup)
• KB5003695 (Security Only)
• KB5003697 (Monthly Rollup)
• KB5003696 (Security Only)

Sourced from Microsoft Security Update Guide (CVRF document 2021-Jun).

CISA due date

Federal deadline: November 17, 2021.Federal agencies must complete the required action by this date. For private SMBs the deadline is advisory — but treat it as a strong recommendation, especially if you handle regulated data (HIPAA, GLBA, ABA model rules).

EPSS

EPSS score: 3.0% — higher than 86% of all scored CVEs.

EPSS estimates the probability of exploitation activity in the next 30 days. Every entry on this site is already confirmed exploited, so read it as relative urgency among the things you still have open, not as permission to wait.

Score dated 2026-07-09, from the FIRST.org Exploit Prediction Scoring System.

Other exploited Microsoft Enhanced Cryptographic Provider entries

More CISA KEV entries for Microsoft Enhanced Cryptographic Provider. Same product line, same actively-exploited status.

• CVE-2021-31201: Microsoft Enhanced Cryptographic Provider Privilege Escalation Vulnerability

Browse more

• All Microsoft KEV entries
• All SMB-relevant KEV entries

Source

Pulled daily from the public cisagov/kev-data mirror (CC0). View the original entry on cisa.gov. CISA KEV is US-Government public-domain data; we add the SMB-vertical framing and the coping action above.