CVE-2026-50522: Microsoft SharePoint Remote Code Execution Vulnerability
Actively exploited. At least one CVE in this advisory is listed in the CISA Known Exploited Vulnerabilities catalog — exploitation has been observed in the wild. Treat remediation as urgent.
Deserialization of untrusted data in Microsoft Office SharePoint allows an unauthorized attacker to execute code over a network.
CSIRTS triage
- What
- Deserialization of untrusted data allows an unauthorized attacker to execute code over a network.
- Who is affected
- Deployments of Microsoft Office SharePoint that are vulnerable to this remote code execution.
- Urgency
- Remediation is critical due to the critical severity and potential for remote code execution.
- Action
- Update Microsoft SharePoint to the latest version immediately.
AI-assisted analysis generated from the source advisory — verify against the original.
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Details
Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-50522
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Exploitation confirmedCVE-2026-50522Already exploited in the wild (CISA KEV) — the prediction phase is over. Patch now. Riskier than 99% of all scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-50522 | coverage & exploitation status | NVD · CVE.org |
Same CVEs, other sources
How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.
- unknownexploitedSecurity Alert: [Updated] Microsoft Releases July 2026 Security Updatesjpcert
- criticalexploitedMicrosoft security advisory – July 2026 monthly rollup (AV26-698) – Update 3cccs
- criticalexploited2026-009: Critical Vulnerabilities in Microsoft SharePointcert-eu
- highexploitedCISA Adds Two Known Exploited Vulnerabilities to Catalogcisa
- criticalexploitedCVE-2026-50522: Microsoft SharePoint Deserialization of Untrusted Data Vulnerabilitycisa-kev
- unknownexploitedMultiple vulnerabilities in Microsoft Sharepoint (July 22, 2026)cert-fr-alerte
- unknownexploitedNCSC-2026-0237 [1.02] [H/H] Vulnerabilities Fixed in Microsoft Officencsc-nl
- unknownexploitedNCSC-2026-0237 [1.01] [H/H] Vulnerabilities fixed in Microsoft Officencsc-nl
- unknownMultiple vulnerabilities in Microsoft products (July 15, 2026)cert-fr-avis
- unknownexploitedNCSC-2026-0237 [1.00] [M/H] Vulnerabilities fixed in Microsoft Officencsc-nl
- criticalCVE-2026-50522: Deserialization of untrusted data in Microsoft Office SharePoint allows an unauthorized attack…nvd
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