CYBERSIXT Signal Over Noise
All CVEs
Vulnerability intelligence

CVE-2026-45659

Microsoft SharePoint Server Deserialization of Untrusted Data Vulnerability

Microsoft SharePoint Server CWE-502

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

CVSS Score
8.8
High
EPSS — Exploit Probability
9.1%
Riskier than 95% of all CVEs
Exploitation
Confirmed in the wild
Used in ransomware campaigns
Remediation
Patch available
Federal deadline 2026-07-04
CISA required action

Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines. Deadline for federal agencies: 2026-07-04.

NVD entry Vendor patch PoC / advisory CISA KEV

12 articles across 8 outlets · first covered May 26, 2026 · latest Jul 22, 2026

Tracked incidents

vulnerability open 16 articles
CISA adds Check Point and SharePoint flaws to Known Exploited Vulnerabilities catalog

Coverage timeline

Related CVEs — Microsoft

CVE-2026-33825KEV CVE-2026-42897KEV CVE-2026-41091KEV CVE-2008-4250KEV CVE-2009-1537KEV CVE-2010-0249KEV CVE-2010-0806KEV CVE-2026-45498KEV