How severe is CVE-2025-9611?

CVE-2025-9611 has a CVSS 4.0 base score of 7.2, rated high severity.

Is CVE-2025-9611 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (63rd percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2025-9611?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2025-9611 have an EU (EUVD) identifier?

Yes. CVE-2025-9611 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-1179.

When was CVE-2025-9611 published?

CVE-2025-9611 was published on 2026-01-07 and last updated on 2026-06-17.

CVE-2025-9611

CVE-2025-9611 is a high-severity vulnerability with a CVSS 4.0 base score of 7.2. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-749.

Key facts

Severity: High (CVSS 4.0 base score 7.2)
EPSS exploit prediction: 1% (63rd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-1179
Weakness: CWE-749
Published: 2026-01-07
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is 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.
How severe is CVE-2025-9611?: CVE-2025-9611 has a CVSS 4.0 base score of 7.2, rated high severity.
Is CVE-2025-9611 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (63rd percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2025-9611?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2025-9611 have an EU (EUVD) identifier?: Yes. CVE-2025-9611 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-1179.
When was CVE-2025-9611 published?: CVE-2025-9611 was published on 2026-01-07 and last updated on 2026-06-17.

References

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