CVE-2026-50522: Microsoft SharePoint

What is CVE-2026-50522?

Deserialization of untrusted data in Microsoft Office SharePoint allows an unauthorized attacker to execute code over a network.

CVSS9.8 NVD 3.1

SeverityCRITICAL

Exploitation In the wild In CISA KEV

EPSS3% · P87

Triage statusActive Exploit

ActionPatch immediately

CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CWECWE-502

NVD published2026-07-14

NVD last modified2026-07-23

Timeline

2026-07-14Published to the U.S. National Vulnerability Database (NVD)
2026-07-22First covered in a defend.network daily briefing
2026-07-22Added to the CISA Known Exploited Vulnerabilities (KEV) catalog
2026-07-23NVD record last updated
2026-07-25CISA federal remediation deadline (BOD 22-01)

CISA Known Exploited Vulnerability

Microsoft SharePoint Deserialization of Untrusted Data Vulnerability

Added to KEV2026-07-22

Federal patch deadline2026-07-25

Known ransomware useUnknown

Affected product

Microsoft SharePoint

Remediation Steps

Apply the vendor security update for Microsoft Sharepoint Server as a priority.
Restrict network exposure of the affected service to trusted sources until patched.
Review logs and detections for indicators of exploitation.
Confirm fixed versions against the official vendor advisory before deploying.

References

Referenced in our briefings & reports

Vulnerability Priority Report – Week 3 of August 2026 (August 17 – 23)
Vulnerability Priority Report – Week 2 of August 2026 (August 10 – 16)
Vulnerability Priority Report – Week 1 of August 2026 (August 3 – 9)
Vulnerability Priority Report – Week 4 of July 2026 (July 27 – August 2)
Vulnerability Priority Report – Week 3 of July 2026 (July 20 – 26)
Microsoft 570 patches, Check Point KEV; BlueNoroff crypto phishing escalates (2026-07-25)
Zimbra zero-day exploited by Laundry Bear; Langflow RCE added to KEV (2026-07-24)
SharePoint RCE, WordPress flaws, PAN-OS actively exploited in ransomware campaigns (2026-07-22)

Browse all tracked CVEs in the defend.network CVE database →

🤖 This CVE page is generated by defend.network from NVD, CISA KEV, EPSS, and our verified daily briefings. Severity and exploitation data come from official sources; always verify remediation steps against the official vendor advisory before acting in production.