CVE-2025-9611

Microsoft Playwright MCP Server versions prior to 0.0.40 fails to validate the Origin header on incoming connections. This allows an attacker to perform a DNS rebinding attack via a victim’s web browser and send unauthorized requests to a locally running MCP server, resulting in unintended invocation of MCP tool endpoints.

CVSS 4.0

7.2CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:H/SC:L/SI:L/SA:L

EPSS

1.2% chance of exploitation in the next 30 days; higher than 68% of CVEs (scores of 2026-10-25)

CWE

CWE-749

Published

2026-01-07

Modified

2026-10-08

Record from

the NVD, synced 2026-10-19

Packages (OSV)

References

• https://github.com/JLLeitschuh/security-research/security/advisories/GHSA-8rgw-6xp9-2fg3
• https://github.com/microsoft/playwright/commit/1313fbd
• https://www.vulncheck.com/advisories/microsoft-playwright-mcp-server-dns-rebinding-via-missing-origin-header-validation

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