CVE-2020-0977Network attack vector

Authenticated script execution via unsanitized web requests

Published Apr 15, 2020 · Updated Aug 4, 2024

Cross-site scripting in Microsoft SharePoint 2013 Service Pack 1, 2016, and 2019 allows remote authenticated users to run script via crafted requests. SharePoint fails to sanitize attacker-controlled content in a specially crafted web request before returning it in a page viewed by another user. Exploitation requires low-privilege authentication and victim interaction; script executes in the victim's browser context, enabling unauthorized reads or actions within that user's SharePoint access.

CVSS severity5.4
Medium
EPSS probability1.63%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in Microsoft SharePoint 2013 Service Pack 1, 2016, and 2019 allows remote authenticated users to run script via crafted requests. SharePoint fails to sanitize attacker-controlled content in a specially crafted web request before returning it in a page viewed by another user. Exploitation requires low-privilege authentication and victim interaction; script executes in the victim's browser context, enabling unauthorized reads or actions within that user's SharePoint access.

The record

CVE
CVE-2020-0977
Published
Apr 15, 2020
Updated
Aug 4, 2024
Vendor
Microsoft
Product
Microsoft SharePoint Server
Classifications
T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 15, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record 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=2019

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Microsoft · Microsoft SharePoint Serverversion=2019
Microsoft · Microsoft SharePoint Enterprise Serverversion=2013 Service Pack 1; version=2016

Published CVSS scores

5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
3.5NIST NVDAV:N/AC:M/Au:S/C:N/I:P/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1059.007Command and Scripting Interpreter JavaScript/JScript

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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