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Security researchers at OX Security disclosed multiple vulnerabilities across widely used Microsoft Visual Studio Code extensions—Live Server, Code Runner, Markdown Preview Enhanced, and Microsoft Live Preview—with combined installs reported at 125–128 million. The issues enable attacks ranging from local file exfiltration to arbitrary code/JavaScript execution, and highlight how a single vulnerable or malicious extension can be leveraged for broader compromise and potential lateral movement in developer environments.
Reported flaws include CVE-2025-65717 (Live Server; CVSS 9.1) enabling local file theft by luring a developer to a malicious site while the extension’s local server is running (e.g., localhost:5500), CVE-2025-65716 (Markdown Preview Enhanced; CVSS 8.8) allowing arbitrary JavaScript execution via a crafted .md file with subsequent local port enumeration and exfiltration, and CVE-2025-65715 (Code Runner; CVSS 7.8) enabling code execution by tricking users into modifying settings.json. Separate reporting on Microsoft Live Preview describes a one-click reflected XSS and unauthenticated request abuse against the extension’s local development server to enumerate and exfiltrate sensitive files (e.g., .env, API keys, source code); this Live Preview issue was reported as patched in version 0.4.16 via input sanitization (e.g., an escapeHTML function), while other extension issues were described as unpatched at the time of reporting.
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7 events from the most recent confirmed update back to the earliest known activity.
OX Security published its findings, warning that flaws in four VS Code extensions with more than 125 million installs exposed developers to file exfiltration, XSS, and remote code execution. The disclosure highlighted IDE extensions as a supply-chain weak point that could enable lateral movement inside organizations.
OX Security said the extension-related issues were also confirmed in Cursor and Windsurf, extending the impact beyond standard VS Code deployments. This showed the risk applied across compatible IDE ecosystems used by developers.
The vulnerabilities affecting Code Runner, Markdown Preview Enhanced, and Live Server were assigned CVE-2025-65715, CVE-2025-65716, and CVE-2025-65717, respectively. Reports described these issues as affecting all versions of the impacted extensions and remaining unpatched at disclosure time.
Microsoft released Live Preview version 0.4.16, fixing the XSS-to-file-exfiltration issue by adding HTML sanitization. Multiple reports say the patch was released without public acknowledgment and no CVE was assigned.
OX Security researchers Nir Zadok and Moshe Siman Tov Bustan reported the Microsoft Live Preview one-click XSS and local file exfiltration issue to Microsoft. Microsoft initially assessed the issue as low severity because exploitation required specific conditions and user interaction.
OX Security began coordinated disclosure of the extension vulnerabilities to maintainers in July 2025, using channels including email, GitHub, and social media. The disclosures covered the non-Microsoft extensions later tracked as CVE-2025-65715, CVE-2025-65716, and CVE-2025-65717.
OX Security researchers discovered severe vulnerabilities affecting four popular Visual Studio Code extensions: Live Server, Code Runner, Markdown Preview Enhanced, and Microsoft Live Preview. The flaws could enable local file theft, JavaScript execution, remote code execution, and XSS-based exfiltration from developer environments.
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Researchers disclosed multiple high-severity vulnerabilities in widely used Visual Studio Code extensions, including **Live Server**, **Markdown Preview Enhanced**, **Code Runner**, and **Microsoft Live Preview**, exposing developers to local file theft, cross-site scripting, data exfiltration, and remote code execution. Three issues were assigned identifiers `CVE-2025-65715`, `CVE-2025-65716`, and `CVE-2025-65717`, with separate disclosures highlighting flaws in **Markdown Preview Enhanced** and **Live Server**. The most severe issue, `CVE-2025-65717` in **Live Server**, could allow a remote unauthenticated attacker to exfiltrate files from a developer workstation through localhost access if the victim opens a malicious website. Security guidance accompanying the disclosures urged organizations to update affected VS Code extensions to fixed versions, restrict installed extensions to those that are necessary, and prefer trusted publishers to reduce developer workstation exposure.
Jul 24, 2026
Security researchers at **Ox Security** reported multiple high-to-critical vulnerabilities in widely used *Visual Studio Code* extensions—collectively exceeding **128 million downloads**—that could enable **local file exfiltration** and **code execution** in developer environments. The issues highlighted include **Live Server** (**CVE-2025-65717**), **Code Runner** (**CVE-2025-65715**, referenced in reporting but not included as a CVE entry here), **Markdown Preview Enhanced** (**CVE-2025-65716**), and *Microsoft Live Preview* (no CVE cited in the reporting). Ox Security stated it attempted disclosure starting in June 2025 but did not receive responses from maintainers, warning that exploitation could support **lateral movement**, **data theft**, and **system takeover** in corporate networks where developer workstations are a pivot point. The CVE records included in this set describe two of the extension flaws in more detail: **CVE-2025-65717** (Live Server v5.7.9) allows attackers to **exfiltrate files** when a user interacts with a crafted HTML page, and **CVE-2025-65716** (Markdown Preview Enhanced v0.8.18) can lead to **arbitrary code execution** via a crafted `.md` file (user interaction required). Other items in the feed are unrelated, covering a broad mix of independent vulnerabilities (e.g., Tenable Security Center command injection, LightLLM unsafe deserialization RCE, libvpx heap overflow affecting Firefox/Thunderbird, and multiple router/IoT hard-coded credential and command-injection issues) and should not be treated as part of the VSCode-extension disclosure story.
Jun 29, 2026
Microsoft disclosed and patched multiple **elevation of privilege** vulnerabilities affecting **Visual Studio Code** and its **JS Debug Extension**, including `CVE-2025-24039`, `CVE-2025-24042`, and `CVE-2026-41613`. The latest issue, `CVE-2026-41613`, is rated **Important** with a **CVSS 3.1 score of 8.8** and is described as a **session fixation** flaw mapped to `CWE-384` and `CWE-78`. Microsoft said the vulnerability affects Visual Studio Code itself, while the earlier 2025 advisories cover separate privilege-escalation bugs in the core product and the JS Debug Extension. According to Microsoft, exploitation of `CVE-2026-41613` requires **user interaction**, specifically convincing a target to open a malicious file in VS Code, and could allow an attacker to obtain the permissions of the **MCP Server’s managed identity**. Microsoft said the flaw was **not publicly disclosed** and **not exploited** at the time of release, assessed exploitation as **less likely**, and made a fix available; the issue was credited to **Elad Luz of Oasis Security** through coordinated disclosure.
Jun 29, 2026