Microsoft SharePoint Server Privilege Escalation Vulnerability
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.
- Vendor
- Microsoft
- Product
- SharePoint Server
- CVSS
- 9.8
- EPSS (exploit probability)
- 100.0%
- Status
- kevransomware use
- CISA patch-by (BOD 22-01)
- Added to KEV
Is CVE-2023-29357 being exploited?
Yes. CISA added CVE-2023-29357 to its Known Exploited Vulnerabilities catalog on . CISA only lists a CVE when it has reliable evidence of exploitation in the wild. CISA marks it as known to be used in ransomware campaigns.
FIRST's EPSS model puts the probability of exploitation activity in the next 30 days at 100.0% (scored October 14, 2026).
- CISA KEV[ LISTED ]
- ENISA EUVD (exploited)[ — ]
- CIRCL KEV[ — ]
Catalog snapshot 2026-11-13. Full cross-catalog view: /kev-comparison
CVE-2023-29357 timeline
Every event links to its source. Catalog dates are each catalog's own; day offsets count from NVD publication. Data: JSON
What to do
CISA required actionApply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
US federal civilian agencies must remediate by (21 days after listing) under BOD 22-01. Everyone else: that deadline is a sensible upper bound, not a target. Vendor guidance and the NVD record are linked under Source above.
Other Microsoft SharePoint CVEs we track
| CVE / Vulnerability | Severity | CVSS | EPSS | Added to KEV |
|---|---|---|---|---|
| CVE-2026-65660 Microsoft SharePoint Code Injection Vulnerabilitywrite-up | [ HIGH ] | 8.8 | 9.9% | |
| CVE-2026-55040 SharePoint Server JWT token authentication bypasswrite-up | [ CRITICAL ] | 9.1 | 69.5% | |
| CVE-2026-50522 SharePoint Server deserialization of untrusted data RCEwrite-up | [ CRITICAL ] | 9.8 | 3.0% | |
| CVE-2026-58644 Microsoft SharePoint deserialization of untrusted data (unauth RCE)write-up | [ CRITICAL ] | 9.8 | 15.9% | |
| CVE-2026-56164 SharePoint Server elevation of privilege — missing authentication for critical functionwrite-up | [ MEDIUM ] | 5.3 | 27.3% | |
| CVE-2026-45659 Microsoft SharePoint Server deserialization remote code executionransomware usewrite-up | [ HIGH ] | 8.8 | 80.2% | |
| CVE-2026-32201 SharePoint Server spoofing via improper input validationwrite-up | [ MEDIUM ] | 6.5 | 44.0% | |
| CVE-2026-20963 Microsoft SharePoint Deserialization of Untrusted Data Vulnerability | [ CRITICAL ] | 9.8 | 29.2% |