CVE-2026-50522 - Microsoft SharePoint Deserialization of Untrusted Data Vulnerability (known exploited)
Added to CISA KEV on 2026-07-22. Microsoft SharePoint contains a deserialization of untrusted data vulnerability which could allow an unauthorized attacker to execute code over a network.
CRITICAL
CISA KEV
ACTIVELY EXPLOITED
Severity & confidence
Source severitycritical
Platform severitycritical
Confidenceconfirmed
Exploitationactively exploited
CVSS-
Affected
Vendorsmicrosoft
ProductsSharePoint
CountriesEU
Reporting sources (3)
CISA - Known Exploited Vulnerabilities
Microsoft Security Response Center - Update Guide
CERT-EU - Security Advisories
๐ฏ Why should I care?
- On the CISA Known Exploited Vulnerabilities list.
- Credible sources report active exploitation in the wild.
Timeline & provenance
Published2026-07-22T00:00:00
Last updated2026-10-21T06:41:46
Ingested2026-08-21T04:39:09
FreshnessNEAR-REAL-TIME
Threat typeexploitation
Recommended action
Apply the vendor-supplied patch immediately. Review vendor and CISA guidance for detection and mitigation.
Next steps
- Identify affected systems in your environment.
- Apply the vendor patch or mitigation guidance.
- Review logs for indicators described in the advisory.
- Follow the affected vendor/product to track updates.
Confidence explanation
This object is reported by 3 independent sources.
Source type: gov ยท Original: CISA - Known Exploited Vulnerabilities
