Loading story…
A security issue in Visual Studio Code versions 1.19.0 through 1.19.2 exposed the extension host with the Node.js debugging flag enabled, causing it to listen on local TCP port 9333. That debugger interface could be reached through the Chrome DevTools Protocol, allowing an attacker to interact with the running process and inject arbitrary code into VS Code.
The reported attack path used DNS rebinding from a malicious web page to access the localhost debug endpoint, retrieve the WebSocket debugger URL, and execute commands against the exposed debugger service. The flaw was addressed in VS Code 1.19.3, and users of affected releases were urged to upgrade; the report also noted that manually starting VS Code with an inspect flag could still expose a similar local debugging risk.
See affected versions and whether adversaries are exploiting it.
4 events from the most recent confirmed update back to the earliest known activity.
On 2018-03-16, a public write-up described how the exposed localhost debug endpoint in VS Code could be exploited, including DNS rebinding and Chrome DevTools Protocol Runtime.evaluate to inject code into the VS Code process.
The write-up states that Node.js officially fixed the remote debugging protocol issue in its March 2018 security releases, addressing related exposure in the debugging protocol.
The issue was fixed in Visual Studio Code 1.19.3, which removed the unintended listener on port 9333 from the extension host startup behavior. Users on affected versions were advised to upgrade.
Visual Studio Code versions 1.19.0 through 1.19.2 accidentally launched the extension host with the Node.js --inspect flag, exposing a debugger interface on localhost TCP port 9333 that could allow arbitrary code execution via the Chrome DevTools Protocol.
Vulnerabilities, threat actors, malware, products, organizations, and breaches Mallory has linked to this story.
See whether adversaries are exploiting this yet, and where the affected versions run in your environment.
2 references tracked. Mallory keeps watching after this page renders.
Map indicators from this story to your assets and identify affected systems in minutes.
Every observed campaign, victim, and pivot linked to actors named in this story.
Malware, exploits, and IOCs connected to the activity described here.
YARA, Sigma, and Snort rules deployed to your SIEM as soon as they’re published.
Get matching new stories delivered to your team as they break — not the next morning.
Ask questions about this story and take action on the answers.
Other stories Mallory is tracking that overlap on entities, sources, or topic labels.
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** 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
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