Patch tracker / CVE reference / CVE-2026-20963

CVE-2026-20963

Critical severity Microsoft vulnerability, CVSS 9.8. Fixed by 3 Microsoft security updates.

CriticalCISA KEV

Risk summary

CVSS base
9.8
EPSS exploit probability
31%
Severity
Critical

Exploitation and severity

Listed in the CISA Known Exploited Vulnerabilities catalog, confirmed exploited in the wild. EPSS exploit probability 31%. CVSS 9.8 (Critical).

This CVE is among the lower half of tracked Microsoft CVEs by EPSS exploit probability, and one of 3 actively-exploited CVEs in January 2026.

What to do

Treat as urgent: it is being exploited in the wild (CISA KEV), so patch ahead of items that are not. In Intune or Defender, confirm whether the fixing updates KB5002822, KB5002825, KB5002828 are installed across the affected products. Senserva does this automatically across your tenant and flags every missing patch.

Official patch for CVE-2026-20963

Apply the Microsoft security updates below to fix CVE-2026-20963. Each KB page links to the Microsoft Update Catalog download for every affected product.

KB5002822KB5002825KB5002828

Affected products

  • Microsoft Office 2016 (32-bit edition)
  • Microsoft Office 2016 (64-bit edition)
  • Microsoft SharePoint Server 2019

Authoritative references

NVD detailMicrosoft MSRCCISA KEV catalogFIRST.org EPSS

Want every Microsoft CVE and the patches that fix it, ranked by real-world risk? See the Microsoft Patch Tracker.

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Lexicon: the terms on this page
CVE
Common Vulnerabilities and Exposures. A unique ID for one publicly known vulnerability, such as CVE-2025-1234.
KB
Microsoft Knowledge Base article. The identifier for a specific Microsoft update.
KEV
CISA Known Exploited Vulnerabilities. CVEs confirmed exploited in the wild. Fix these first.
CVSS
Common Vulnerability Scoring System. A standardized Severity score from 0 to 10.
EPSS
Exploit Prediction Scoring System. The probability a CVE will be exploited in the next 30 days.
MSRC
Microsoft Security Response Center. Microsoft's Patch Tuesday advisories and KB-to-CVE mapping.
NVD
National Vulnerability Database (NIST). Authoritative CVE metadata and CVSS scores.
Ransomware
The vulnerability is linked to known ransomware activity.