CVE-2026-31837
Received Received - Intake
JWKS Resolver Failure in Istio Exposes Hardcoded Credentials

Publication date: 2026-03-10

Last updated on: 2026-03-18

Assigner: GitHub, Inc.

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 user of Istio is impacted if the JWKS resolver becomes unavailable or the fetch fails, exposing hardcoded defaults regardless of use of the RequestAuthentication resource. This vulnerability is fixed in 1.29.1, 1.28.5, and 1.27.8.
CVSS Scores
EPSS Scores
Probability:
Percentile:
Meta Information
Published
2026-03-10
Last Modified
2026-03-18
Generated
2026-06-16
AI Q&A
2026-03-11
EPSS Evaluated
2026-06-14
NVD
CVE-2026-31837
EUVD
EUVD-2026-10938
Affected Vendors & Products
Showing 3 associated CPEs
Vendor Product Version / Range
istio istio to 1.27.8 (exc)
istio istio From 1.28.0 (inc) to 1.28.5 (exc)
istio istio From 1.29.0 (inc) to 1.29.1 (exc)
Helpful Resources
Exploitability
CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-200 The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.
Attack-Flow Graph
AI Quick Actions
Instant insights powered by AI
Executive Summary

This vulnerability affects Istio, an open platform used to connect, manage, and secure microservices. Before versions 1.29.1, 1.28.5, and 1.27.8, if the JWKS (JSON Web Key Set) resolver became unavailable or if fetching the keys failed, Istio would expose hardcoded default keys. This exposure happens regardless of whether the RequestAuthentication resource is used, potentially allowing unauthorized access or bypassing authentication mechanisms.

Impact Analysis

The impact of this vulnerability is that an attacker could exploit the failure of the JWKS resolver to cause Istio to use hardcoded default keys. This could lead to unauthorized access to microservices or bypassing of authentication controls, compromising the security of applications relying on Istio for service-to-service authentication.

Compliance Impact

I don't know

Detection Guidance

I don't know

Mitigation Strategies

To mitigate this vulnerability, upgrade Istio to version 1.29.1, 1.28.5, or 1.27.8 or later, as these versions contain the fix for the issue where the JWKS resolver becomes unavailable or fetch fails, exposing hardcoded defaults.

Chat Assistant
Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-31837. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70
EPSS Chart