CVE-2026-20963
CriticalExploitedPublic exploitMicrosoft SharePoint Remote Code Execution Vulnerability
Published Jan 13, 2026 · Updated Jul 30, 2026
Key Facts
Patch immediately- CVE-2026-20963 is a critical-severity vulnerability (CVSS 9.8 v3.1) affecting Sharepoint Server (Microsoft), Sharepoint Server 2016 (Microsoft), Sharepoint Server 2019 (Microsoft) and 2 more products.
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Mar 12, 2026. Public exploit code is available.
- EPSS estimates a 29% probability of exploitation in the next 30 days.
- Fixed versions are available, including Microsoft SharePoint Enterprise Server 2016 16.0.5535.1001, Sharepoint Server 16.0.19127.20442, Sharepoint Server 2019 16.0.10417.20083.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
9.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
29%
Higher than 98.1% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2026-20963 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
Description
Deserialization of untrusted data in Microsoft Office SharePoint allows an unauthorized attacker to execute code over a network.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Mar 18, 2026 | Mar 21, 2026 | Not reported |
| Industry KEV feed | Mar 18, 2026 | Mar 21, 2026 | Not reported |
| CIRCL KEV | Mar 12, 2026 | Mar 21, 2026 | Not reported |
| ENISA EUVD | Mar 12, 2026 | n/a | Not reported |
Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Affected Products
9 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Sharepoint ServerMicrosoft | 2016, 2019 | 16.0.19127.20442 |
| Sharepoint Server 2016Microsoft | See advisory | n/a |
| Sharepoint Server 2019Microsoft | >= 16.0.0 | 16.0.10417.20083 |
| Microsoft SharePoint Enterprise Server 2016 | >= 16.0.0 | 16.0.5535.1001 |
| Microsoft SharePoint Server Subscription Edition | >= 16.0.0 | 16.0.19127.20442 |
Patched Releases
Microsoft SharePoint Enterprise Server 2016
16.0.5535.1001
Sharepoint Server
16.0.19127.20442
Sharepoint Server 2019
16.0.10417.20083
Microsoft SharePoint Server Subscription Edition
16.0.19127.20442
Timeline
Publicly disclosed
Jan 13, 2026
Added to CIRCL KEV
Mar 12, 2026
Added to ENISA EUVD
Mar 12, 2026
Added to CISA KEV
Mar 18, 2026
Added to Industry KEV feed
Mar 18, 2026
Last updated
Jul 30, 2026
Weakness Type
- CWE-502 Deserialization of Untrusted Data
References
- advisoryMicrosoft SharePoint Remote Code Execution Vulnerability
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
FAQ
Common Questions.
Deserialization of untrusted data in Microsoft Office SharePoint allows an unauthorized attacker to execute code over a network.
Affected: Sharepoint Server (Microsoft) versions 2016, 2019; Sharepoint Server 2016 (Microsoft); Sharepoint Server 2019 (Microsoft) versions >= 16.0.0, among others. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Mar 12, 2026.
Yes. It was added on Mar 18, 2026 with a federal remediation due date of Mar 21, 2026.
Public exploit code is available.
Fixed versions are available, including Microsoft SharePoint Enterprise Server 2016 16.0.5535.1001, Sharepoint Server 16.0.19127.20442, Sharepoint Server 2019 16.0.10417.20083.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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