# CVE-2025-55234: Windows SMB Elevation of Privilege Vulnerability > Attackers can exploit SMB relay attacks to elevate privileges if SMB signing and Extended Protection for Authentication are not enabled. - **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** A user has to click or open something - **Fix available:** No - **Published:** 9 Sep 2025 - **Updated:** 26 Feb 2026 - **Also known as:** GHSA-9x8h-hfmc-8j5r ## What is CVE-2025-55234? CVE-2025-55234 is a high-severity authentication bypass vulnerability in Microsoft Windows 10 1507, published on 9 Sep 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link. ### Official description SMB Server might be susceptible to relay attacks depending on the configuration. An attacker who successfully exploited these vulnerabilities could perform relay attacks and make the users subject to elevation of privilege attacks. The SMB Server already supports mechanisms for hardening against relay attacks: SMB Server signing SMB Server Extended Protection for Authentication (EPA) Microsoft is releasing this CVE to provide customers with audit capabilities to help them to assess their environment and to identify any potential device or software incompatibility issues before deploying SMB Server hardening measures that protect against relay attacks. If you have not already enabled SMB Server hardening measures, we advise customers to take the following actions to be protected from these relay attacks: Assess your environment by utilizing the audit capabilities that we are exposing in the September 2025 security updates. See Support for Audit Events to deploy SMB Server Hardening—SMB Server Signing & SMB Server EPA. Adopt appropriate SMB Server hardening measures. Weakness: CWE-287 (Improper Authentication) ## Which versions are affected by CVE-2025-55234? It affects 15 products. Products: Microsoft Windows 10 1507, Microsoft Windows 10 1607, Microsoft Windows 10 1809, Microsoft Windows 10 21h2, Microsoft Windows 10 22h2, Microsoft Windows 11 22h2, Microsoft Windows 11 23h2, Microsoft Windows 11 24h2, Microsoft Windows Server 2008, Microsoft Windows Server 2012, Microsoft Windows Server 2016, Microsoft Windows Server 2019, Microsoft Windows Server 2022, Microsoft Windows Server 2022 23h2, Microsoft Windows Server 2025. ## How do I fix CVE-2025-55234? No fix has been published for CVE-2025-55234 yet. Limit exposure of the affected software until one is available. ## Is CVE-2025-55234 being exploited? There is no known exploitation of CVE-2025-55234 in the wild and no public exploit code. Public exploit code: - This vulnerability allows attackers to perform relay attacks against the SMB (Server Message Block) protocol. If successful, it can lead to Elevation of Privilege (EoP) essentially allowing unauthorized users to gain higher-level access on a system (github_poc): https://github.com/mrk336/CVE-2025-55234 - This playbook outlines detection, containment, and remediation strategies for CVE-2025-55234, a critical Windows SMB privilege escalation flaw. (github_poc): https://github.com/mrk336/Patch-the-Path-CVE-2025-55234-Detection-Defense ## Other vulnerabilities in Microsoft Windows 10 1507 - [CVE-2017-8543](https://insights.sbomify.com/CVE-2017-8543/): Microsoft Windows Search Remote Code Execution (critical 9.8, exploited in the wild) - [CVE-2025-33053](https://insights.sbomify.com/CVE-2025-33053/): Microsoft Windows External Control of File Name or Path (high 8.8, exploited in the wild) - [CVE-2025-33073](https://insights.sbomify.com/CVE-2025-33073/): Microsoft Windows SMB Client Improper Access Control (high 8.8, exploited in the wild) - [CVE-2024-49039](https://insights.sbomify.com/CVE-2024-49039/): Microsoft Windows Task Scheduler Privilege Escalation (high 8.8, exploited in the wild) - [CVE-2024-43461](https://insights.sbomify.com/CVE-2024-43461/): Microsoft Windows MSHTML Platform Spoofing (high 8.8, exploited in the wild) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2025-55234 and fix it if it is affected. What it is: CVE-2025-55234 is a high-severity authentication bypass vulnerability in Microsoft Windows 10 1507, published on 9 Sep 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link. Exploitation: There is no known exploitation of CVE-2025-55234 in the wild and no public exploit code. Affected product: Microsoft Windows 10 1507. No package-level version data is available, so check the vendor advisory linked from the reference page. Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2025-55234/ (Markdown: https://insights.sbomify.com/CVE-2025-55234/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2025-55234 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-55234 - OSV: https://osv.dev/vulnerability/CVE-2025-55234 --- From sbomify Insights: https://insights.sbomify.com/CVE-2025-55234/ Summaries are generated and may contain mistakes; the official description above is the record.