CVE-2026-25188
Published: 10 March 2026
Summary
CVE-2026-25188 is a high-severity Heap-based Buffer Overflow (CWE-122) vulnerability in Microsoft Windows 10 21H2. Its CVSS base score is 8.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 41.8th 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-10 (Information Input Validation) and SI-16 (Memory Protection).
Deeper analysis
CVE-2026-25188 is a heap-based buffer overflow vulnerability, classified under CWE-122, affecting the Windows Telephony Service. Published on 2026-03-10T18:18:35.780, it carries a CVSS v3.1 base score of 8.8 (AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), indicating high severity due to its potential for significant impact.
An unauthorized attacker positioned on an adjacent network can exploit this vulnerability with low attack complexity, requiring no privileges or user interaction. Exploitation enables privilege escalation, granting the attacker high levels of access to confidentiality, integrity, and availability of the affected system.
The Microsoft Security Response Center (MSRC) has published an update guide detailing patches and mitigation measures at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-25188.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-10661
Vulnerability details
Heap-based buffer overflow in Windows Telephony Service allows an unauthorized attacker to elevate privileges over an adjacent network.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Heap-based buffer overflow in Windows Telephony Service exploitable by unauthorized adjacent network attacker for privilege escalation, directly enabling T1068 (Exploitation for Privilege Escalation).
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Requires timely patching of the specific heap-based buffer overflow in Windows Telephony Service as detailed in the MSRC update guide.
Provides memory safeguards like randomization and non-executable regions to block exploitation of heap buffer overflows even if unpatched.
Enforces validation of network inputs to Windows Telephony Service to prevent malformed data from triggering the buffer overflow.