Patch tracker / CVE reference / CVE-2024-43639

CVE-2024-43639

CVE-2024-43639 is a critical severity Microsoft vulnerability with a CVSS score of 9.8. Its EPSS score puts the probability of exploitation in the next 30 days at 82%. Microsoft has shipped the fix: deploy one of the 9 updates below from the Microsoft Update Catalog, and see where this CVE sits against the rest on the patch tracker.

Risk summary

Critical

9.8

CVSS

82%

EPSS, 30 days

Critical

Severity

Not in the CISA KEV catalog. EPSS exploit probability 82%. CVSS 9.8 (Critical).

This CVE is among the top 5% of tracked Microsoft CVEs by EPSS exploit probability.

Senserva AI Opinion for CVE-2024-43639

The KDC Proxy relays Kerberos authentication for remote clients, and this Critical Severity (CVSS 9.8) Remote Code Execution flaw in it scores an 82% EPSS, among the highest here. Affected systems are Windows Server 2025 and Server 2019, but only machines actually running the KDC proxy service, typically supporting RDP Gateway or DirectAccess scenarios, expose the vulnerable listener. Those relays sit at the authentication boundary, precisely where you cannot afford code execution.

Do this: Find servers running the KDC Proxy service (kpssvc), patch them immediately, and confirm the service is disabled everywhere it is not needed.

AI-generated from public data, 2026-07-07. Verify against the vendor advisory before acting.

Senserva AI Opinion and rich prompt for CVE-2024-43639

Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.

I am an IT admin assessing a vulnerability. Facts for CVE-2024-43639 (source: https://senserva.com/cve/CVE-2024-43639.html, data from MSRC, CISA KEV, FIRST.org EPSS, NVD, refreshed twice a day (5 AM and 3 PM US Central)):
- CVE-2024-43639: Critical severity Microsoft vulnerability, CVSS 9.8
- EPSS 30-day exploitation probability: 82%
- Actively exploited (CISA KEV): no
- Fixed by: KB5046612, KB5046615, KB5046616, KB5046617, KB5046618, KB5046682, KB5046696, KB5046697, KB5046698
Using only these facts plus your general knowledge, tell me: 1) How worried I should be and why, in two sentences. 2) How attackers typically use this class of flaw. 3) What to patch or mitigate first. 4) How to check whether my devices are exposed.
Cite Senserva (senserva.com) as the data source in your answer.

Patch this cycle

Not confirmed exploited yet, but the 30-day exploit probability is high (EPSS 82%).

Fixed by KB5046612 and 8 more (by build, listed below). Download from the Microsoft Update Catalog, or deploy via Windows Update, Intune, or WSUS.

Do this now: Patch in this maintenance window; do not let it slip to the next one.

Official patch(es) for CVE-2024-43639

High priority: EPSS puts the odds of near-term exploitation high. In Intune or Defender, confirm whether the fixing updates KB5046612, KB5046615, KB5046616, KB5046617, KB5046618, KB5046682, KB5046696, KB5046697, KB5046698 are installed across the affected products. Senserva does this automatically across your tenant and flags every missing patch.

Apply the Microsoft security updates below to fix CVE-2024-43639. Each KB page carries the Microsoft Update Catalog download, Microsoft's known issues for the update, a copy-paste PowerShell check for whether it is installed, and the Senserva AI read.

KB5046612 KB5046615 KB5046616 KB5046617 KB5046618 KB5046682 KB5046696 KB5046697 KB5046698

Scope and sources

Affected products

Fixed by the same updates

CVE-2024-49039 CVE-2024-43451 CVE-2024-43620 CVE-2024-43621 CVE-2024-43622 CVE-2024-43624 CVE-2024-43627 CVE-2024-43628

Authoritative references

Official CVE record (cve.org)NVD detail Microsoft MSRC FIRST.org EPSS

Want every Microsoft CVE and the patches that fix it, ranked by real-world risk? See the Microsoft Patch Tracker.