Patch tracker / CVE reference / CVE-2026-20833

CVE-2026-20833

CVE-2026-20833 is a Microsoft vulnerability that Microsoft rates Important, with a CVSS score of 5.5 (Medium). Its EPSS score puts the probability of exploitation in the next 30 days at 71%. Microsoft has shipped the fix: deploy one of the 11 updates below from the Microsoft Update Catalog, and see where this CVE sits against the rest on the patch tracker.

Risk summary

Medium

5.5

CVSS v3

71%

EPSS, 30 days

Medium

Severity

Not in the CISA KEV catalog. EPSS exploit probability 71%. CVSS 5.5 (Medium).

This CVE is among the top 10% of tracked Microsoft CVEs by EPSS exploit probability.

Senserva AI Opinion for CVE-2026-20833

CVE-2026-20833 is an information disclosure flaw in Windows Kerberos, yet it carries a Critical severity rating with a CVSS score of 9.8 and a 74 percent EPSS exploit probability, which is unusually high for a disclosure bug and points to a network-reachable path against domain authentication. Exposed systems are Windows Server 2019 (including Server Core) and Windows Server 2022, which typically act as domain controllers or Kerberos-facing services. It is not yet in the CISA KEV catalog and has no confirmed ransomware use, but the elevated exploit probability against core authentication infrastructure makes it a priority.

Do this: Apply the Microsoft update for CVE-2026-20833 to all Windows Server 2019 and 2022 hosts, prioritizing domain controllers and any Kerberos-facing servers.

AI-generated from public data, 2026-07-26. Verify against the vendor advisory before acting.

Senserva AI Opinion and rich prompt for CVE-2026-20833

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-2026-20833 (source: https://senserva.com/cve/CVE-2026-20833.html, data from MSRC, CISA KEV, FIRST.org EPSS, NVD, refreshed daily (early morning US Central)):
- CVE-2026-20833: Microsoft vulnerability, Microsoft rating Important, CVSS 5.5 (Medium)
- EPSS 30-day exploitation probability: 71%
- Actively exploited (CISA KEV): no
- Fixed by: KB5073379, KB5073450, KB5073457, KB5073695, KB5073696, KB5073697, KB5073698, KB5073699, KB5073700, KB5073722, KB5073723
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 71%).

Fixed by KB5073379 and 10 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-2026-20833

High priority: EPSS puts the odds of near-term exploitation high. In Intune or Defender, confirm whether the fixing updates KB5073379, KB5073450, KB5073457, KB5073695, KB5073696, KB5073697, KB5073698, KB5073699, KB5073700, KB5073722, KB5073723 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-2026-20833. 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.

KB5073379 KB5073450 KB5073457 KB5073695 KB5073696 KB5073697 KB5073698 KB5073699 KB5073700 KB5073722 KB5073723

Scope and sources

Affected products

Fixed by the same updates

CVE-2026-20805 CVE-2025-6965 CVE-2026-20868 CVE-2026-20856 CVE-2026-20931 CVE-2023-31096 CVE-2024-55414 CVE-2026-20809

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.