Cyber Resilience

CVE-2026-55142

Microsoft Sharepoint Server ≤ 16.0.19725.20434

Published
14 July 2026
Modified
16 July 2026
Patch / advisory
View advisory
CVSS Score v3.1 5.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
EPSS Score 0.0042 35th percentile
Risk Priority 43 floored blend · peak EPSS

Summary

CVE-2026-55142 is a medium-severity Numeric Truncation Error (CWE-197) vulnerability in Microsoft Sharepoint Server. Its CVSS base score is 5.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 35th 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-15 (Development Process, Standards, and Tools) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

Numeric truncation error in Microsoft Office Word allows an unauthorized attacker to disclose information locally.

CWE(s)
CWE-197

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-2026-68804Same product: Microsoft 365 Apps
CVE-2026-44823Same product: Microsoft 365 Apps
CVE-2024-37337Same vendor: Microsoft
CVE-2026-40409Same vendor: Microsoft
CVE-2025-49679Same vendor: Microsoft
CVE-2024-21310Same vendor: Microsoft
CVE-2024-21352Same vendor: Microsoft
CVE-2024-21391Same vendor: Microsoft
CVE-2024-28944Same vendor: Microsoft
CVE-2024-21429Same vendor: Microsoft

Affected Assets

microsoft
365 apps
all versions
microsoft
microsoft 365
all versions
microsoft
office 2019
all versions
microsoft
office 2021
all versions
microsoft
office 2024
all versions
microsoft
sharepoint server
2016, 2019 · ≤ 16.0.19725.20434
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 truncation errors through static analysis, dynamic testing, or code review.

SA-15 Development Process, Standards, and Tools partial match

Documented development standards and tools can mandate use of safe arithmetic libraries or explicit checks against truncation.

SA-8 Security and Privacy Engineering Principles partial match

Engineering principles can require safe type conversions and avoidance of narrowing casts that cause truncation.

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 prevent truncation errors via reviews, static analysis, and safe type handling.

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 truncation bugs through static analysis and fuzzing.

A.8.25 Secure development life cycle partial match
prevents

Secure development lifecycle mandates practices that can catch numeric truncation during design and code review.

A.8.26 Application security requirements partial match
degrades

Application security requirements can specify safe numeric handling and data-type constraints.

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

Secure architecture principles include choosing appropriate data types and avoiding unsafe casts.

A.8.28 Secure coding partial match
prevents

Secure coding standards directly prohibit unsafe narrowing conversions and truncation.

References