How severe is CVE-2026-11624?

CVE-2026-11624 has a CVSS 4.0 base score of 9.4, rated critical severity.

Is CVE-2026-11624 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-11624?

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

Does CVE-2026-11624 have an EU (EUVD) identifier?

Yes. CVE-2026-11624 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-36650.

When was CVE-2026-11624 published?

CVE-2026-11624 was published on 2026-06-13 and last updated on 2026-06-17.

CVE-2026-11624

CVE-2026-11624 is a critical-severity vulnerability with a CVSS 4.0 base score of 9.4. 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-346.

Key facts

Severity: Critical (CVSS 4.0 base score 9.4)
EPSS exploit prediction: 0% (5th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-36650
Weakness: CWE-346
Published: 2026-06-13
Last modified: 2026-06-17

Description

The Model Context Protocol has a security warning advising servers to validate the "Origin" header on all incoming connections to prevent DNS rebinding attacks. Prior to the v0.25.0 release, users had no way to validate the origin's host. In v0.25.0, a new "--allowed-hosts" flag was introduced alongside the existing "--allowed-origins" flag, enabling users to specify permitted hosts at server startup. Both flags default to "*", allowing users to implement strict access controls as needed without breaking existing setups. If either flag is set to "*", the server will output a startup warning about potential vulnerabilities. Documentation has also been updated to highlight these security considerations.

Frequently asked questions

What is CVE-2026-11624?: The Model Context Protocol has a security warning advising servers to validate the "Origin" header on all incoming connections to prevent DNS rebinding attacks. Prior to the v0.25.0 release, users had no way to validate the origin's host. In v0.25.0, a new "--allowed-hosts" flag was introduced alongside the existing "--allowed-origins" flag, enabling users to specify permitted hosts at server startup. Both flags default to "*", allowing users to implement strict access controls as needed without breaking existing setups. If either flag is set to "*", the server will output a startup warning about potential vulnerabilities. Documentation has also been updated to highlight these security considerations.
How severe is CVE-2026-11624?: CVE-2026-11624 has a CVSS 4.0 base score of 9.4, rated critical severity.
Is CVE-2026-11624 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-11624?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-11624 have an EU (EUVD) identifier?: Yes. CVE-2026-11624 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-36650.
When was CVE-2026-11624 published?: CVE-2026-11624 was published on 2026-06-13 and last updated on 2026-06-17.

References

Other CWE-346 vulnerabilities

CVE-2026-42901 — Critical (CVSS 10.0): Origin validation error in Microsoft Entra ID allows an unauthorized attacker to elevate privileges over a network.
CVE-2026-6508 — Critical (CVSS 9.8): Origin Validation Error vulnerability in TUBITAK BILGEM Software Technologies Research Institute Liderahenk allows…
CVE-2026-2790 — Critical (CVSS 9.8): Same-origin policy bypass in the Networking: JAR component. This vulnerability was fixed in Firefox 148, Firefox ESR…
CVE-2022-50925 — Critical (CVSS 9.8): Prowise Reflect version 1.0.9 contains a remote keystroke injection vulnerability that allows attackers to send…
CVE-2025-30466 — Critical (CVSS 9.8): This issue was addressed through improved state management. This issue is fixed in Safari 18.4, iOS 18.4 and iPadOS…
CVE-2024-8487 — Critical (CVSS 9.8): A Cross-Origin Resource Sharing (CORS) vulnerability exists in modelscope/agentscope version v0.0.4. The CORS…

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