Cyber Resilience

CVE-2025-27731

High

Published: 08 April 2025

Published
08 April 2025
Modified
08 July 2025
KEV Added
Patch
CVSS Score v3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0094 76.7th percentile
Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-27731 is a high-severity Improper Input Validation (CWE-20) vulnerability in Microsoft Windows 10 1809. Its CVSS base score is 7.8 (High).

Operationally, ranked in the top 23.3% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

Deeper analysis

CVE-2025-27731 is an improper input validation vulnerability, tracked under CWE-20, that affects OpenSSH for Windows. The flaw carries a CVSS 3.1 base score of 7.8 and permits local privilege escalation when an attacker supplies crafted input to the affected component.

An authorized local attacker can exploit the issue without user interaction to obtain elevated privileges on the host, resulting in full compromise of confidentiality, integrity, and availability within the local security context. The current EPSS score of 0.0094, with a recorded peak of 0.0144, reflects only modest movement and does not indicate a pronounced post-disclosure increase in exploitation interest.

Microsoft has published an advisory for the vulnerability at the Microsoft Security Response Center; practitioners should consult that guidance for available patches and configuration steps.

EU & UK References

Vulnerability details

Improper input validation in OpenSSH for Windows allows an authorized attacker to elevate privileges locally.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

microsoft
windows 10 1809
≤ 10.0.17763.7136 · ≤ 10.0.17763.7136
microsoft
windows 10 21h2
≤ 10.0.19044.5737
microsoft
windows 10 22h2
≤ 10.0.19045.5737
microsoft
windows 11 22h2
≤ 10.0.22621.5189
microsoft
windows 11 23h2
≤ 10.0.22631.5189
microsoft
windows 11 24h2
≤ 10.0.26100.3775
microsoft
windows server 2019
≤ 10.0.17763.7136
microsoft
windows server 2022
≤ 10.0.20348.3453
microsoft
windows server 2022 23h2
≤ 10.0.25398.1551
microsoft
windows server 2025
≤ 10.0.26100.3775

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-20

Security testing and developer training directly verify and enforce proper input validation, reducing exploitability of injection and malformed-data weaknesses.

addresses: CWE-20

Security testing and evaluation at multiple SDLC stages directly detects missing or flawed input validation, with the required remediation process ensuring fixes are applied.

addresses: CWE-20

Directly implements checks on information inputs to reject invalid data before processing.

addresses: CWE-20

Spam protection mechanisms perform filtering and detection on inbound/outbound messages, directly compensating for missing or weak input validation of unsolicited content.

References