DNS Rebinding Vulnerability in Microsoft Playwright MCP Server
CVE-2025-9611

7.2HIGH

Key Information:

Vendor

Microsoft
Status
Playwright
Vendor
CVE Published:
7 January 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2025-9611?

The Microsoft Playwright MCP Server, prior to version 0.0.40, is susceptible to a DNS rebinding vulnerability due to inadequate validation of the Origin header in incoming connections. This flaw could allow attackers to exploit a victim's web browser to send unauthorized requests, potentially causing unintended invocations of MCP tool endpoints. As a result, malicious actors could gain access to sensitive operations on a locally running server, increasing the risk of unauthorized actions.

Affected Version(s)

Playwright 0 < 0.0.40

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2025-9611 - Proof of Concept

References

https://github.com/JLLeitschuh/security-research/security...
technical-descriptionexploit
https://github.com/microsoft/playwright/commit/1313fbd
patch
https://www.vulncheck.com/advisories/microsoft-playwright...
third-party-advisory

CVSS V4

Score:
7.2
Severity:
HIGH
Confidentiality:
Low
Integrity:
Low
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

Jonathan Leitschuh
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CVE-2025-9611 : DNS Rebinding Vulnerability in Microsoft Playwright MCP Server