CVE-2026-45463
Microsoft Office Remote Code Execution Vulnerability
HIGH
8.4
CVSS Score
Published: June 9, 2026 at 05:05 PM UTC
Updated: September 24, 2026 at 01:57 PM UTC
9 products affected across 1 vendorOffice365 AppsOffice 2021
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Severity
HIGH8.4
Exploit prediction
EPSS 0.4%
SSVC
No known exploit
Description
Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.
Affected
Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.
Affected range stops below 16.110.26061317, so it looks safe — our inference, not a vendor statement
Affected range stops below https://aka.ms/OfficeSecurityReleases, so it looks safe — our inference, not a vendor statement
All versions
All versions
16.0.1 ≤ v < 16.0.20131.2002416.0.1
Affected range stops below 16.0.20131.20024, so it looks safe — our inference, not a vendor statement
16.0.0 ≤ v < 16.0.5556.100516.0.0
Affected range stops below 16.0.5556.1005, so it looks safe — our inference, not a vendor statement
19.0.0 ≤ v < https://aka.ms/OfficeSecurityReleases19.0.0
Affected range stops below https://aka.ms/OfficeSecurityReleases, so it looks safe — our inference, not a vendor statement
Affected range stops below 16.110.26061317, so it looks safe — our inference, not a vendor statement
Affected range stops below https://aka.ms/OfficeSecurityReleases, so it looks safe — our inference, not a vendor statement
Affected range stops below 16.110.26061317, so it looks safe — our inference, not a vendor statement
Affected range stops below https://aka.ms/OfficeSecurityReleases, so it looks safe — our inference, not a vendor statement
1.0.0 ≤ v < 16.110.26061317
Affected range stops below 16.110.26061317, so it looks safe — our inference, not a vendor statement
Remediation
No guide yetNo remediation guidance has been written for this CVE yet. What the record does show:
Patch and advisory references
References (1)
Vendor AdvisoryPatch
Source: [email protected]
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45463SSVC — Action Prioritization
SSVCNo known exploitNot automatableTotal impact
SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.
CVSS
8.4HIGHmicrosoft
Vector?
Quick Info
StatusMODIFIED
CWE
CWE-121CWE-191
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