Incorrect authorization in grpc - #VU164412
Published: November 10, 2026
Vulnerability identifier: #VU164412
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-863
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to bypass host-based authorization and invoke restricted RPCs, potentially disclosing or modifying data.
The vulnerability exists due to inconsistent host interpretation in gRPC C-core xDS routing and RBAC when processing HTTP/2 requests containing mismatched host and :authority headers. A remote attacker can send :authority: foo and host: bar to select a route as bar while being authorized as foo, bypassing an RBAC rule denying bar.
Affected software
grpc
Remediation
Install security update from vendor's website.
grpc - addressed in versions 1.84.2, 1.85.1