KEV · Actively exploited
CVE-2026-58644
CRITICAL 9.8
KEV
Deserialization of untrusted data in Microsoft Office SharePoint allows an unauthorized attacker to execute code over a network.
Attack vector : Network
No privileges required
No user interaction
Show raw CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
6.37%
above median
percentile 93.0%
CISA Known Exploited Vulnerability
- Added to KEV
- 2026-07-16
- Remediation deadline
- 2026-07-19
- 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.
- Ransomware
- Unknown (not documented by CISA)