CVE-2025-62554
Published: 09 December 2025
Summary
CVE-2025-62554 is a high-severity Type Confusion (CWE-843) 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 Client Execution (T1203); ranked at the 35.3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 SI-16 (Memory Protection) and SI-2 (Flaw Remediation).
Deeper analysis
CVE-2025-62554 is a type confusion vulnerability (CWE-843), specifically an access of resource using incompatible type, affecting Microsoft Office. Published on 2025-12-09, it carries a CVSS v3.1 base score of 8.4 (AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), indicating high severity due to its potential for significant impact on confidentiality, integrity, and availability.
The vulnerability can be exploited by an unauthorized local attacker with low-complexity methods and no required privileges or user interaction. Successful exploitation enables arbitrary code execution on the affected system, potentially leading to full compromise given the high impact ratings across all security principles.
For mitigation details, refer to the official advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-62554, which provides guidance from Microsoft Security Response Center on patches and workarounds.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-202218
Vulnerability details
Access of resource using incompatible type ('type confusion') in Microsoft Office allows an unauthorized attacker to execute code locally.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Type confusion vulnerability in Microsoft Office enabling arbitrary code execution with no privileges or user interaction, directly facilitating T1203: Exploitation for Client Execution.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly requires identification, reporting, and timely patching of flaws like this type confusion vulnerability in Microsoft Office to prevent exploitation.
Implements memory protections such as ASLR and DEP that directly mitigate type confusion attacks by preventing reliable code execution from memory corruption.
Deploys malicious code protection mechanisms at entry points to scan and block malicious Office files exploiting the type confusion for local code execution.