Cyber Resilience

CVE-2025-54899

Microsoft Office Long Term Servicing Channel 2021 … 2024

Published
09 September 2025
Modified
12 September 2025
Patch / advisory
View advisory
CVSS Score v3.1 7.8
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:H/A:H
EPSS Score 0.0058 45th percentile
Risk Priority 58 floored blend · peak EPSS

Summary

CVE-2025-54899 is a high-severity Free of Memory not on the Heap (CWE-590) vulnerability in Microsoft Office Long Term Servicing Channel. Its CVSS base score is 7.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 45th 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

Free of memory not on the heap in Microsoft Office Excel allows an unauthorized attacker to execute code locally.

CWE(s)
CWE-590

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 →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-36041Same product: Microsoft 365 Apps
CVE-2024-49027Same product: Microsoft 365 Apps
CVE-2024-49069Same product: Microsoft 365 Apps
CVE-2024-49030Same product: Microsoft 365 Apps
CVE-2024-43504Same product: Microsoft 365 Apps
CVE-2024-49028Same product: Microsoft 365 Apps
CVE-2023-35372Same product: Microsoft 365 Apps
CVE-2023-36866Same product: Microsoft 365 Apps
CVE-2023-24953Same product: Microsoft 365 Apps
CVE-2024-43465Same product: Microsoft 365 Apps

Affected Assets

microsoft
365 apps
all versions
microsoft
excel
2016
microsoft
office
2019
microsoft
office long term servicing channel
2021, 2024

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation (static/dynamic analysis) can discover incorrect free() calls on non-heap memory.

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

Documented development standards and tools can require correct heap allocation/deallocation discipline, stopping the defect at introduction.

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 incorrect free() calls via code review, static analysis, and developer training.

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 in development can detect invalid-free defects before release.

A.8.25 Secure development life cycle partial match
prevents

Secure development lifecycle mandates memory-safety practices that reduce use-after-free and invalid-free bugs.

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

Secure architecture and engineering principles include disciplined memory management that prevents freeing non-heap memory.

A.8.28 Secure coding partial match
prevents

Secure coding standards explicitly forbid freeing pointers not obtained from heap allocators, directly mitigating CWE-590.

References