On 2026-07-16, CISA added CVE-2026-58644 (Microsoft SharePoint) to its Known Exploited Vulnerabilities (KEV) catalog [2]. The vulnerability is listed in the catalog as "Microsoft SharePoint Deserialization of Untrusted Data Vulnerability" [2]. CISA requires remediation in accordance with the listed vendor mitigation guidance; see the original text in the body for specific requirements [2].
Backfill: this event became public on Jul 16, 2026 and we added it on Nov 10, 2026. It is not a new event.
CISA Adds Microsoft SharePoint Vulnerability CVE-2026-58644 to Known Exploited Vulnerabilities Catalog
1 min read
- Disclosed
- Jul 16, 2026
- Published
- Nov 10, 2026
- Last updated
- Nov 8, 2026
- CVSS basis
- Our assessment
- 15.9%, higher than 97% of CVEs
- Exploitation and patch status
- ExploitedKEV
- Attack vector
- Vulnerability status
- Actor type
- Motivation
On this page
30-second summary
What happened
Who is affected
Industries mainly affected: Government, Cross-industry
What to do nowOur advice
CISA requires remediation in accordance with the listed vendor mitigation guidance; see the original text in the body for specific requirements [2].
Timeline
Technical details
CISA KEV Listing Record
CISA added CVE-2026-58644 (Microsoft SharePoint) to the Known Exploited Vulnerabilities () catalog on 2026-07-16 [2].
Original Technical Description
Microsoft SharePoint contains a deserialization of untrusted data vulnerability that allows an unauthorized attacker to execute code over a network. [2]
Official 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. [2]
Individual Vulnerability Record
The U.S. National Vulnerability Database (NVD) provides an independent vulnerability record and description for CVE-2026-58644 [1].
References
Official / primary3
- [1]
“Deserialization of untrusted data in Microsoft Office SharePoint allows an unauthorized attacker to execute code over a network.”
- [2]CISA2026-07-16Accessed 2026-11-07
This site aggregates public information and is not security consulting advice. Test remediation steps before applying.