CVE-2025-53760Network attack vector

Privilege escalation via Exchange Calendar Overlay SSRF

Published Aug 12, 2025 · Updated Feb 13, 2026

Server-side request forgery in Microsoft SharePoint Server allows remote authenticated users to elevate privileges over a network. The Exchange Calendar Overlay feature causes the server to issue attacker-directed HTTP requests, but Microsoft has not disclosed the flawed request field or validation path. Low-privileged network access and no user interaction are required; affected versions are Server 2016 before 16.0.5513.1002, Server 2019 before 16.0.10417.20041, and Subscription Edition before 16.0.18526.20518.

CVSS severity7.1
High
EPSS probability12.75%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Server-side request forgery in Microsoft SharePoint Server allows remote authenticated users to elevate privileges over a network. The Exchange Calendar Overlay feature causes the server to issue attacker-directed HTTP requests, but Microsoft has not disclosed the flawed request field or validation path. Low-privileged network access and no user interaction are required; affected versions are Server 2016 before 16.0.5513.1002, Server 2019 before 16.0.10417.20041, and Subscription Edition before 16.0.18526.20518.

The record

CVE
CVE-2025-53760
Published
Aug 12, 2025
Updated
Feb 13, 2026
Vendor
Microsoft
Product
Microsoft SharePoint Enterprise Server 2016
Classifications
CWE-918, T1068
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 12, 2025CVE publishedPublication date reported by the CVE source.
  2. Feb 13, 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.

  1. Affected versionversion=16.0.0 <16.0.5513.1002

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Microsoft · Microsoft SharePoint Enterprise Server 2016version=16.0.0 <16.0.5513.1002
Microsoft · Microsoft SharePoint Server 2019version=16.0.0 <16.0.10417.20041
Microsoft · Microsoft SharePoint Server Subscription Editionversion=16.0.0 <16.0.18526.20518

Published CVSS scores

7.1Microsoft CorporationCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-918Server-Side Request Forgery (SSRF)
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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