CVE-2023-29357: in the CISA KEV catalogue

Microsoft SharePoint Server Privilege Escalation Vulnerability. CISA added CVE-2023-29357 to the Known Exploited Vulnerabilities catalogue on 2024-01-10 with a default due date of 2024-01-31. Known ransomware campaign use: Known. Forensic triage flag: No.

Microsoft SharePoint Server contains an unspecified vulnerability that allows an unauthenticated attacker, who has gained access to spoofed JWT authentication tokens, to use them for executing a network attack. This attack bypasses authentication, enabling the attacker to gain administrator privileges. (CISA description)

Vendor / product

Microsoft SharePoint Server

CWE

CWE-303

CISA required action

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

EPSS

100%, percentile 99 (scored 2026-11-03)

EPSS puts nearly every time in 100 odds (100%) on exploitation activity being observed in the next 30 days. Its score is higher than or equal to that of 99% of scored CVEs. This is a model estimate about exploitation anywhere, not about your environment.

Your own deadline under CISA BOD 26-04 depends on exposure, automatability and technical impact: work it out with the BOD 26-04 calculator.