Patch tracker / CVE reference / CVE-2026-58634

CVE-2026-58634

CVE-2026-58634 is a high severity Microsoft vulnerability with a CVSS score of 7.8. Its EPSS score puts the probability of exploitation in the next 30 days at 64%. Microsoft has shipped the fix: deploy the update below from the Microsoft Update Catalog, and see where this CVE sits against the rest on the patch tracker.

Risk summary

High

7.8

CVSS

64%

EPSS, 30 days

High

Severity

Not in the CISA KEV catalog. EPSS exploit probability 64%. CVSS 7.8 (High).

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

Senserva AI Opinion for CVE-2026-58634

CVE-2026-58634 is a Desktop Window Manager elevation of privilege flaw that only affects Windows 11 version 26H1 on x64 and ARM64 systems, so exposure is limited to that specific and recent build rather than older Windows 11 releases. DWM runs with high privileges on every interactive session, which is why a local attacker who already has code execution can use it to escalate to SYSTEM. Severity is rated High with a CVSS score of 7.8, and it is not currently listed in CISA KEV nor tied to known ransomware.

Do this: Inventory devices running Windows 11 version 26H1 on x64 and ARM64 and deploy the DWM patch to those specific builds first.

AI-generated from public data, 2026-07-21. Verify against the vendor advisory before acting.

Senserva AI Opinion and rich prompt for CVE-2026-58634

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-2026-58634 (source: https://senserva.com/cve/CVE-2026-58634.html, data from MSRC, CISA KEV, FIRST.org EPSS, NVD, refreshed twice a day (5 AM and 3 PM US Central)):
- CVE-2026-58634: High severity Microsoft vulnerability, CVSS 7.8
- EPSS 30-day exploitation probability: 64%
- Actively exploited (CISA KEV): no
- Fixed by: KB5101649
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 64%).

Fixed by KB5101649. 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-2026-58634

High priority: EPSS puts the odds of near-term exploitation high. In Intune or Defender, confirm whether the fixing update KB5101649 are installed across the affected products. Senserva does this automatically across your tenant and flags every missing patch.

Apply the Microsoft security update below to fix CVE-2026-58634. 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.

KB5101649

Scope and sources

Affected products

Fixed by the same update

CVE-2026-32202 CVE-2026-50302 CVE-2026-50416 CVE-2026-50419 CVE-2026-57092 CVE-2026-42990 CVE-2026-49172 CVE-2026-50447

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.