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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.
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4 events from the most recent confirmed update back to the earliest known activity.
CSIRT.SK published an advisory summarizing Ox Security's findings on critical vulnerabilities in Visual Studio Code extensions. The advisory recommended updating affected extensions to fixed versions and limiting installed extensions to only those necessary and from trusted sources.
Ox Security researchers identified serious vulnerabilities in several popular Visual Studio Code extensions, including Live Server, Code Runner, Markdown Preview Enhanced, and Microsoft Live Preview. The issues included local file theft, cross-site scripting, data exfiltration, and remote code execution, with CVEs assigned to three of the flaws.
A vulnerability tracked as CVE-2025-65717 was disclosed in the Live Server VS Code extension. CSIRT.SK described it as the most severe issue, allowing a remote unauthenticated attacker to exfiltrate files from a developer machine via localhost access when the victim opens a malicious website.
A vulnerability tracked as CVE-2025-65716 was disclosed in the Markdown Preview Enhanced VS Code extension. The flaw was part of Ox Security's reporting on critical extension security issues affecting developers.
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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.
Jun 29, 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