Patch tracker / CVE reference / CVE-2026-42833

CVE-2026-42833

CVE-2026-42833 is a critical severity Microsoft vulnerability with a CVSS score of 9.9. 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

Critical

9.9

CVSS

1.2%

EPSS, 30 days

Critical

Severity

Not in the CISA KEV catalog. EPSS exploit probability 1.2%. CVSS 9.9 (Critical).

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

Senserva AI Opinion for CVE-2026-42833

The second Critical Severity (CVSS 9.9) Remote Code Execution flaw disclosed against Microsoft Dynamics 365 on-premises version 9.1 in this period, which suggests researchers are actively working over that product's attack surface. EPSS is 1% and there is no KEV entry, but two top-rated RCEs in the same on-prem business platform is a trend worth respecting. Dynamics servers hold customer and financial data and often sit outside routine patch automation.

Do this: Bundle this with CVE-2026-42898 into a single Dynamics 365 on-premises maintenance window and verify the servers are shielded from direct internet access.

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

Senserva AI Opinion and rich prompt for CVE-2026-42833

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-2026-42833 (source: https://senserva.com/cve/CVE-2026-42833.html, data from MSRC, CISA KEV, FIRST.org EPSS, NVD, refreshed twice a day (5 AM and 3 PM US Central)):
- CVE-2026-42833: Critical severity Microsoft vulnerability, CVSS 9.9
- EPSS 30-day exploitation probability: 1.2%
- Actively exploited (CISA KEV): no
- Fixed by: KB5078943
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.

Schedule normally

No exploitation observed: not in the CISA KEV catalog, EPSS 1%.

Fixed by KB5078943. Download from the Microsoft Update Catalog, or deploy via Windows Update, Intune, or WSUS.

Do this now: Deploy with your normal update cycle. This page refreshes daily; the verdict changes the day the data does.

Official patch(es) for CVE-2026-42833

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 update KB5078943 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-2026-42833. 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.

KB5078943

Scope and sources

Affected products

Fixed by the same update

CVE-2026-33103 CVE-2026-42898

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.