Patch tracker / CVE reference / CVE-2025-27729

CVE-2025-27729

CVE-2025-27729 is a Microsoft vulnerability that Microsoft rates Important, with a CVSS score of 7.8 (High). Its EPSS score puts the probability of exploitation in the next 30 days at 14%. Microsoft has shipped the fix: deploy one of the 3 updates below from the Microsoft Update Catalog, and see where this CVE sits against the rest on the patch tracker.

Our data comes from Microsoft, CISA and other public sources, and it can be wrong or out of date. If you are unsure, check the linked source before you act, and tell us when we are wrong so we can fix it.

Risk summary

High

7.8

CVSS v3

14%

EPSS, 30 days

High

Severity

Not in the CISA KEV catalog. EPSS exploit probability 14%. CVSS 7.8 (High).

This CVE is among the top 25% of tracked Microsoft CVEs by EPSS exploit probability.

Senserva AI Opinion for CVE-2025-27729

Remote code execution through the Windows Shell itself, affecting Windows 10 21H2 across 32-bit, x64, and ARM64, at High Severity, CVSS 8.8. Shell bugs typically fire when a user browses to or previews malicious content, so exposure is broad on client machines. EPSS is 18 percent.

Do this: Push the Windows 10 21H2 cumulative update to end-user devices ahead of servers this cycle.

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

Senserva AI Opinion and rich prompt for CVE-2025-27729

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-2025-27729 (source: https://senserva.com/cve/CVE-2025-27729.html, data from MSRC, CISA KEV, FIRST.org EPSS, NVD, refreshed daily (early morning US Central)):
- CVE-2025-27729: Microsoft vulnerability, Microsoft rating Important, CVSS 7.8 (High)
- EPSS 30-day exploitation probability: 14%
- Actively exploited (CISA KEV): no
- Fixed by: KB5055518, KB5055523, KB5055528
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 14%).

Fixed by KB5055518 and 2 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-2025-27729

Elevated priority: high severity or a meaningful exploitation probability, sooner if an affected product is internet-facing. In Intune or Defender, confirm whether the fixing updates KB5055518, KB5055523, KB5055528 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-2025-27729. 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.

KB5055518 KB5055523 KB5055528

Scope and sources

Affected products

Fixed by the same updates

CVE-2025-29824 CVE-2025-21205 CVE-2025-21221 CVE-2025-21222 CVE-2025-26647 CVE-2025-26669 CVE-2025-27477 CVE-2025-27481

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.