Istio up to 1.27.7/1.28.4/1.29.0 information disclosure

Summaryinfo

A vulnerability was found in Istio up to 1.27.7/1.28.4/1.29.0. It has been classified as problematic. Affected is an unknown function. This manipulation causes information disclosure. This vulnerability appears as CVE-2026-31837. The attack may be initiated remotely. There is no available exploit. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability classified as problematic was found in Istio up to 1.27.7/1.28.4/1.29.0. Affected by this vulnerability is an unknown code block. The manipulation with an unknown input leads to a information disclosure vulnerability. The CWE definition for the vulnerability is CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. As an impact it is known to affect confidentiality. The summary by CVE is:

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.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-31837 since 03/09/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1592 for this issue.

Upgrading to version 1.27.8, 1.28.5 or 1.29.1 eliminates this vulnerability.

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Productinfo

Name

• Istio

Version

• 1.0
• 1.1
• 1.2
• 1.3
• 1.4
• 1.5
• 1.6
• 1.7
• 1.8
• 1.9
• 1.10
• 1.11
• 1.12
• 1.13
• 1.14
• 1.15
• 1.16
• 1.17
• 1.18
• 1.19
• 1.20
• 1.21
• 1.22
• 1.23
• 1.24
• 1.25
• 1.26
• 1.27
• 1.27.0
• 1.27.1
• 1.27.2
• 1.27.3
• 1.27.4
• 1.27.5
• 1.27.6
• 1.27.7
• 1.28
• 1.28.0
• 1.28.1
• 1.28.2
• 1.28.3
• 1.28.4
• 1.29.0

Website

• Product: https://github.com/istio/istio/

CPE 2.3info

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