Patch tracker / CVE reference / CVE-2026-55045

CVE-2026-55045

CVE-2026-55045 is a high severity Microsoft vulnerability with a CVSS score of 8.4. Its EPSS score puts the probability of exploitation in the next 30 days at 77%. Microsoft has shipped the fix: deploy one of the 6 updates below from the Microsoft Update Catalog, and see where this CVE sits against the rest on the patch tracker.

Risk summary

High

8.4

CVSS

77%

EPSS, 30 days

High

Severity

Not in the CISA KEV catalog. EPSS exploit probability 77%. CVSS 8.4 (High).

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

Senserva AI Opinion for CVE-2026-55045

CVE-2026-55045 is a Critical (CVSS 9.8) remote code execution flaw spanning both on-premises SharePoint (Enterprise Server 2016 and Server 2019) and Microsoft 365 Apps for Enterprise on 32-bit systems, an unusually broad mix of server and client footprints. It is not yet in CISA KEV and has no known ransomware use, but the 57 percent EPSS score signals exploitation is more likely than not in the near term. SharePoint servers are typically internet-facing and hold sensitive business content, so a 9.8 RCE there is a direct path to full compromise.

Do this: Prioritize patching your SharePoint 2016 and 2019 servers first, then roll out the update to 32-bit Microsoft 365 Apps clients.

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

Senserva AI Opinion and rich prompt for CVE-2026-55045

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-2026-55045 (source: https://senserva.com/cve/CVE-2026-55045.html, data from MSRC, CISA KEV, FIRST.org EPSS, NVD, refreshed twice a day (5 AM and 3 PM US Central)):
- CVE-2026-55045: High severity Microsoft vulnerability, CVSS 8.4
- EPSS 30-day exploitation probability: 77%
- Actively exploited (CISA KEV): no
- Fixed by: KB5002882, KB5002883, KB5002885, KB5002887, KB5002891, KB5002892
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 77%).

Fixed by KB5002882 and 5 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-2026-55045

High priority: EPSS puts the odds of near-term exploitation high. In Intune or Defender, confirm whether the fixing updates KB5002882, KB5002883, KB5002885, KB5002887, KB5002891, KB5002892 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-2026-55045. 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.

KB5002882 KB5002883 KB5002885 KB5002887 KB5002891 KB5002892

Scope and sources

Affected products

Fixed by the same updates

CVE-2026-50522 CVE-2026-56164 CVE-2026-70306 CVE-2026-55040 CVE-2026-55052 CVE-2026-58277 CVE-2026-50301 CVE-2026-50314

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.