Authenticated privilege escalation via unsafe deserialization
Published Jun 9, 2026 · Updated Jun 9, 2026
Deserialization of untrusted data in Microsoft SharePoint Server allows remote authenticated users to elevate privileges over a network. Microsoft has not disclosed the affected deserialization locus, serialized data format, or validation failure that accepts the untrusted input. A low-privileged SharePoint account is required; successful exploitation grants actions reserved for a higher-privileged context.
Summary
What happened
Deserialization of untrusted data in Microsoft SharePoint Server allows remote authenticated users to elevate privileges over a network. Microsoft has not disclosed the affected deserialization locus, serialized data format, or validation failure that accepts the untrusted input. A low-privileged SharePoint account is required; successful exploitation grants actions reserved for a higher-privileged context.
The record
- CVE
- CVE-2026-45484
- Published
- Jun 9, 2026
- Updated
- Jun 9, 2026
- Vendor
- Microsoft
- Product
- Microsoft SharePoint Enterprise Server 2016
- Classifications
- CWE-502, T1068
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Jun 9, 2026CVE publishedPublication date reported by the CVE source.
- Jun 9, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=16.0.0 <16.0.5556.1005
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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