CVE-2023-33129Network attack vector

Authenticated service interruption via heap buffer overflow

Published Jun 13, 2023 · Updated Feb 28, 2025

Heap-based buffer overflow in Microsoft SharePoint Server allows remote authenticated users to interrupt service through network requests. Microsoft identifies the weakness but has not published the affected routine, request field, or corrupting operation. A low-privileged authenticated account is required; successful exploitation affects availability only and can interrupt the SharePoint service.

CVSS severity6.5
Medium
EPSS probability1.98%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Heap-based buffer overflow in Microsoft SharePoint Server allows remote authenticated users to interrupt service through network requests. Microsoft identifies the weakness but has not published the affected routine, request field, or corrupting operation. A low-privileged authenticated account is required; successful exploitation affects availability only and can interrupt the SharePoint service.

The record

CVE
CVE-2023-33129
Published
Jun 13, 2023
Updated
Feb 28, 2025
Vendor
Microsoft
Product
Microsoft SharePoint Enterprise Server 2016
Classifications
CWE-122, T1499
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 13, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 28, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=16.0.0 <16.0.5400.1001

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Microsoft · Microsoft SharePoint Enterprise Server 2016version=16.0.0 <16.0.5400.1001
Microsoft · Microsoft SharePoint Server 2019version=16.0.0 <16.0.10399.20005
Microsoft · Microsoft SharePoint Server Subscription Editionversion=16.0.0 <16.0.16130.20548

Published CVSS scores

6.5Microsoft CorporationCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

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

CWE-122Heap-based Buffer Overflow
T1499Endpoint Denial of Service

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo