Cyber Resilience

CVE-2025-53733

Microsoft Office Long Term Servicing Channel 2021 … 2024

Published
12 August 2025
Modified
17 June 2026
Patch / advisory
View advisory
CVSS Score v3.1 8.4
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0050 40th percentile
Risk Priority 64 floored blend · peak EPSS

Summary

CVE-2025-53733 is a high-severity Incorrect Conversion between Numeric Types (CWE-681) vulnerability in Microsoft Office Long Term Servicing Channel. Its CVSS base score is 8.4 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 40th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2025-53733 is an incorrect numeric type conversion vulnerability, tracked under CWE-681, that affects Microsoft Office Word. The flaw carries a CVSS 3.1 base score of 8.4 and permits an attacker to execute arbitrary code on an affected system when a specially crafted document is processed.

An unauthorized attacker with local access and no user interaction or privileges can exploit the issue to achieve full code execution, resulting in complete compromise of confidentiality, integrity, and availability on the target host. The attack vector is strictly local, limiting remote exploitation without prior access to the system.

Microsoft has published an advisory detailing the vulnerability and available updates at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-53733. The associated EPSS score remains low and unchanged at 0.0143, indicating no significant increase in observed exploitation interest since disclosure.

EU & UK References

Vulnerability Data

Incorrect conversion between numeric types in Microsoft Office Word allows an unauthorized attacker to execute code locally.

CWE(s)
CWE-681

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-21736Same product: Microsoft 365 Apps
CVE-2024-49065Same product: Microsoft 365 Apps
CVE-2023-36762Same product: Microsoft 365 Apps
CVE-2024-21379Same product: Microsoft 365 Apps
CVE-2023-33149Same product: Microsoft 365 Apps
CVE-2023-33152Same product: Microsoft 365 Apps
CVE-2023-33153Same product: Microsoft 365 Apps
CVE-2023-28311Same product: Microsoft 365 Apps
CVE-2023-33146Same product: Microsoft 365 Apps
CVE-2023-36045Same product: Microsoft 365 Apps

Affected Assets

microsoft
365 apps
all versions
microsoft
office
2019
microsoft
office long term servicing channel
2021, 2024
microsoft
sharepoint enterprise server
2016
microsoft
sharepoint server
2019
microsoft
word
2016

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation can discover incorrect numeric conversions through targeted test cases.

SA-8 Security and Privacy Engineering Principles partial match

Engineering principles can mandate safe numeric handling and range checks that structurally avoid bad conversions.

SI-10 Information Input Validation partial match

Input validation directly stops malformed or out-of-range numeric values from reaching conversion logic.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require code reviews, static analysis, and developer training that catch and prevent numeric type-conversion errors.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing can detect numeric conversion defects before release.

A.8.25 Secure development life cycle partial match
prevents

Secure development lifecycle includes type-safety and conversion checks that reduce numeric truncation risks.

A.8.26 Application security requirements partial match
prevents

Application security requirements can mandate safe numeric handling and range validation.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles promote strong typing and safe conversion practices.

A.8.28 Secure coding partial match
prevents

Secure coding standards directly address correct numeric type conversions and overflow checks.

References