CVE-2023-29357: Microsoft SharePoint Server Privilege Escalation Vulnerability
Actively exploited. At least one CVE in this advisory is listed in the CISA Known Exploited Vulnerabilities catalog — exploitation has been observed in the wild. Treat remediation as urgent.
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.
CSIRTS triage
- What
- An unauthenticated attacker can use spoofed JWT authentication tokens to gain administrator privileges.
- Who is affected
- Deployments of Microsoft SharePoint Server that are vulnerable to this attack.
- Urgency
- Remediation is urgent due to the critical nature of the vulnerability and confirmed exploitation.
- Action
- Apply the latest security patch provided by Microsoft.
AI-assisted analysis generated from the source advisory — verify against the original.
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Details
Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2023-29357
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Exploitation confirmedCVE-2023-29357Already exploited in the wild (CISA KEV) — the prediction phase is over. Patch now. Riskier than 100% of all scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2023-29357 | coverage & exploitation status | NVD · CVE.org |
Recent advisories for Microsoft SharePoint Server
A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.
- criticalexploitedAL26-015 - Critical vulnerability impacting Microsoft SharePoint Server – CVE-2026-45659cccs · 2026-07-02
- high[UPDATE] [high] Microsoft SharePoint Server 2016 and SharePoint Server 2019: Vulnerability allows code executi…cert-bund · 2026-07-02
- criticalexploitedCVE-2026-45659: Microsoft SharePoint Server Deserialization of Untrusted Data Vulnerabilitycisa-kev · 2026-07-01
- mediumCVE-2026-45468: Microsoft SharePoint Server Spoofing Vulnerabilitymsrc · 2026-06-09
- mediumCVE-2026-45467: Microsoft SharePoint Server Spoofing Vulnerabilitymsrc · 2026-06-09
- mediumCVE-2026-45479: Microsoft SharePoint Server Spoofing Vulnerabilitymsrc · 2026-06-09
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