CVE-2026-58644
Microsoft SharePoint Deserialization of Untrusted Data Vulnerability
Published Jul 14, 2026 · updated Jul 16, 2026 · Microsoft SharePoint
Microsoft SharePoint contains a deserialization of untrusted data vulnerability that allows an unauthorized attacker to execute code over a network.
Timeline
Detection, updates, and resolution for this record.
Jul 14, 2026 · Catalog
Detected
Microsoft SharePoint contains a deserialization of untrusted data vulnerability that allows an unauthorized attacker to execute code over a network.
Jul 16, 2026 · CISA KEV
Known exploited
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
Jul 16, 2026 · Catalog
Updated
Microsoft SharePoint contains a deserialization of untrusted data vulnerability that allows an unauthorized attacker to execute code over a network.
Jul 19, 2026 · CISA KEV
Remediation due
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
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.
CISA due date Jul 19, 2026
Affected
- cpe microsoft/sharepoint serverversion unspecified
- cpe microsoft/sharepoint server2016
- cpe microsoft/sharepoint server2019
- vendor Microsoft SharePointversion unspecified
Sources
- CISA KEVCVE-2026-58644
Microsoft SharePoint contains a deserialization of untrusted data vulnerability that allows an unauthorized attacker to execute code over a network.
cisa.gov - CVE.orgCVE-2026-58644
Official CVE identifier
cve.org - FIRST EPSSCVE-2026-58644
30-day exploitation probability 15.9%
first.org - NIST NVDCVE-2026-58644
Deserialization of untrusted data in Microsoft Office SharePoint allows an unauthorized attacker to execute code over a network.
nvd.nist.gov