CVE-2026-37236 — CRITICAL (9.8)

Vulnerability Description

grpc-gateway v2.28.0 is vulnerable to Incorrect Access Control. The application processes the X-HTTP-Method-Override header in ServeMux.ServeHTTP without restricting allowed methods. When a POST request with Content-Type application/x-www-form-urlencoded includes this header, the request method is rewritten to an arbitrary attacker-supplied value before routing. This allows bypassing method-based access controls enforced by upstream proxies or WAFs.

CVSS Score

9.8

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

HIGH

Integrity

HIGH

Availability

HIGH

Related Weaknesses (CWE)

CWE-639

References

FAQ

What is CVE-2026-37236?

CVE-2026-37236 is a vulnerability with a CVSS score of 9.8 (CRITICAL). grpc-gateway v2.28.0 is vulnerable to Incorrect Access Control. The application processes the X-HTTP-Method-Override header in ServeMux.ServeHTTP without restricting allowed methods. When a POST reque...

How severe is CVE-2026-37236?

CVE-2026-37236 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.

Is there a patch for CVE-2026-37236?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.