CVE-2026-37236CWE-639

CVE-2026-37236

Critical · published August 28, 2026

CVSS v3.1
9.8
EPSS
0%
Percentile
36.7
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
9.8 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00434 · 36.7th percentile
Weakness
CWE-639 · Authorization Bypass Through User-Controlled Key
Published
2026-08-28T20:17Z
References (3)
https://github.com/grpc-ecosystem/grpc-gateway · [email protected]https://github.com/grpc-ecosystem/grpc-gateway/commit/72123cd4f32545f6e1376873f412dcdcbcf29acc · [email protected]https://s00me00ne.com/cve/cve-2026-37236/ · [email protected]
EPSS history
Timeline
  • 30 AUG 16:17Z
    EPSS moved — → 0%
    epss
  • 28 AUG 00:00Z
    grpc-gateway v2.28.0 is vulnerable to Incorrect Access Control
    cvelistv5