Istio is an open platform to connect, manage, and secure microservices. Prior to 1.29.1, 1.28.5, and 1.27.8, a vulnerability in Envoy RBAC header matching could allow authorization policy bypass when policies rely on HTTP headers that may contain multiple values. An attacker could craft requests with multiple header values in a way that causes Envoy to evaluate the header differently than intended, potentially bypassing authorization checks. This may allow unauthorized requests to reach protected services when policies depend on such header-based matching conditions. This vulnerability is fixed in 1.29.1, 1.28.5, and 1.27.8.
History

Wed, 11 Mar 2026 14:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 11 Mar 2026 12:00:00 +0000

Type Values Removed Values Added
First Time appeared Istio
Istio istio
Vendors & Products Istio
Istio istio

Tue, 10 Mar 2026 22:15:00 +0000

Type Values Removed Values Added
Description Istio is an open platform to connect, manage, and secure microservices. Prior to 1.29.1, 1.28.5, and 1.27.8, a vulnerability in Envoy RBAC header matching could allow authorization policy bypass when policies rely on HTTP headers that may contain multiple values. An attacker could craft requests with multiple header values in a way that causes Envoy to evaluate the header differently than intended, potentially bypassing authorization checks. This may allow unauthorized requests to reach protected services when policies depend on such header-based matching conditions. This vulnerability is fixed in 1.29.1, 1.28.5, and 1.27.8.
Title Istio HTTP debug endpoints on port 15014 to enforce namespace-based authorization, preventing cross-namespace proxy data access.
Weaknesses CWE-863
References
Metrics cvssV4_0

{'score': 6.9, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-03-10T21:58:53.354Z

Updated: 2026-03-11T13:53:28.620Z

Reserved: 2026-03-09T17:41:56.078Z

Link: CVE-2026-31838

cve-icon Vulnrichment

Updated: 2026-03-11T13:53:25.008Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-03-10T22:16:21.870

Modified: 2026-03-11T13:52:47.683

Link: CVE-2026-31838

cve-icon Redhat

No data.