Microsoft Office SharePoint
CVE-2026-50522 — Microsoft SharePoint Remote Code Execution Vulnerability
Executive Summary
Deserialization of untrusted data in Microsoft Office SharePoint allows an unauthorized attacker to execute code over a network.
Overview
9.8
CVSS CRITICAL
Critical
MS Severity
Not Exploited
MS Exploit Status
More Likely
MS Exploit Likelihood
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
ATTACK VECTOR
Network
ATTACK COMPLEXITY
Low
PRIVILEGES REQUIRED
None
USER INTERACTION
None
SCOPE
Unchanged
CONFIDENTIALITY
High
INTEGRITY
High
AVAILABILITY
High
EXPLOIT CODE MATURITY
Unproven
REMEDIATION LEVEL
Official Fix
REPORT CONFIDENCE
Confirmed
Temporal Score: 8.5
EPSS Score
0.76981
probability of exploitation in the next 30 days
0.99506 percentile - updated 2026-08-14
View on FIRST.org
Affected Products
3 affected products
| Product | KB Article | Severity | Impact | Restart Required |
|---|---|---|---|---|
| Microsoft SharePoint Enterprise Server 2016 | 5002891 (Security Update) |
Critical | Remote Code Execution | Maybe |
| Microsoft SharePoint Server 2019 | 5002883 (Security Update) |
Critical | Remote Code Execution | Maybe |
| Microsoft SharePoint Server Subscription Edition | 5002882 (Security Update) |
Critical | Remote Code Execution | Maybe |
Patches
3 patches
| Article | Type | Restart |
|---|---|---|
5002891 |
Security Update | Maybe |
5002883 |
Security Update | Maybe |
5002882 |
Security Update | Maybe |
Exploits & PoC
5 public PoCsUnverified third-party code
Public proof-of-concept repositories aggregated from PoC-in-GitHub. They are not reviewed and may be incomplete, non-functional, or malicious — inspect the code before running anything.
| Repository | Stars | Published | Description |
|---|---|---|---|
| 4minx/CVE-2026-50522 | 40 | 2026-07-25 | CVE-2026-50522 PoC |
| WismanSec/sharepoint-2026-poc | 2 | 2026-07-26 | PoC, IOCs, and detection logic for the SharePoint /_trust WS-Federation BinaryFormatter deserialization chain. Lab reconstruction covering unauthenticated RCE, in-process machine key theft, and the ar |
| HORKimhab/CVE-2026-50522 | 0 | 2026-07-22 | CVE-2026-50522 |
| ChPratik/CVE-2026-50522 | 0 | 2026-07-27 | Deserialization of untrusted data in Microsoft Office SharePoint allows an unauthorized attacker to execute code over a network. |
| darses/CVE-2026-50522 | 0 | 2026-07-28 | Microsoft SharePoint CVE-2026-50522 |
Detection Rules
No public Sigma or Nuclei detection rule has been mapped to this CVE yet. Coverage is concentrated on exploited / high-profile vulnerabilities; check SigmaHQ for updates.
Acknowledgments
splitline (@_splitline_) from DEVCORE Research Team working with TrendAI Zero Day Initiative
References
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