Patch tracker / CVE reference / CVE-2026-45501
CVE-2026-45501
Updated July 21, 2026. Data refreshed on every build from MSRC, CISA KEV, and FIRST EPSS.
High severity Microsoft vulnerability, CVSS 8.8. Fixed by 4 Microsoft security updates.
All about CVE-2026-45501: the Senserva AI read, whether it is exploited, the official patches, its change history, and the questions admins ask.
CVE-2026-45501 is a high severity Microsoft vulnerability with a CVSS score of 8.8. Microsoft has shipped the fix: deploy one of the 4 updates below from the Microsoft Update Catalog, and see where this CVE sits against the rest on the patch tracker.
Risk summary
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Senserva AI Opinion for CVE-2026-45501
CVE-2026-45501 is a spoofing flaw in on-premises Microsoft Exchange Server, hitting Subscription Edition RTM plus the current cumulative updates for the 2016 and 2019 lines (CU23 and CU15). Spoofing on Exchange typically means an attacker can forge identity or content in a way that supports phishing or authentication trickery against your mail environment. Severity is rated High with a CVSS of 8.8, though EPSS puts exploit probability at only 6 percent, and it is not in CISA KEV or tied to ransomware.
Do this: Inventory your on-prem Exchange servers and apply Microsoft's security update for the Subscription Edition, 2016 CU23, and 2019 CU15 builds you are running.
AI-generated from public data, 2026-07-21. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for CVE-2026-45501
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Full tracking and change history for CVE-2026-45501
Published and last-revised dates are authoritative, from Microsoft MSRC (or the CISA KEV date-added). Senserva additionally records day-to-day changes from 2026-07-07, refreshed several times a day; the change count reflects that forward-only tracking.
Exploitation and severity
Not in the CISA KEV catalog. EPSS exploit probability 5.6%. CVSS 8.8 (High).
This CVE is among the lower half of tracked Microsoft CVEs by EPSS exploit probability.
Official patch(es) for CVE-2026-45501
Moderate priority: schedule it in your normal patch cycle. In Intune or Defender, confirm whether the fixing updates KB5094139, KB5094140, KB5094142, KB5094144 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-2026-45501. 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.
Affected products
Common questions about CVE-2026-45501
Is CVE-2026-45501 actively exploited?
It is not currently listed in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score puts the probability of exploitation in the next 30 days at 5.6%.
What patch fixes CVE-2026-45501?
Microsoft fixed CVE-2026-45501 in KB5094139, KB5094140, KB5094142, KB5094144. Download from the Microsoft Update Catalog, or let Intune, Windows Update, or WSUS deliver it.
Which products are affected by CVE-2026-45501?
Microsoft Exchange Server 2019 Cumulative Update 14, Microsoft Exchange Server 2019 Cumulative Update 15, Microsoft Exchange Server Subscription Edition RTM.
Can I ask my own AI about CVE-2026-45501?
Yes. This page includes a free, ready-to-paste AI prompt containing CVE-2026-45501's key facts: severity, CVSS, EPSS exploit probability, CISA KEV status, and the fixing KB. Copy it into Claude, ChatGPT, or Copilot for a triage plan; the data is refreshed three times a day (5 AM, 12:30 PM, and 7 PM US Central).
Fixed by the same updates
If you are patching CVE-2026-45501, the same updates also fix these:
Authoritative references
Want every Microsoft CVE and the patches that fix it, ranked by real-world risk? See the Microsoft Patch Tracker.
