Review reviewHigh

CVE-2026-31837

istio istio, Red Hat OpenShift AI 2.25, Red Hat OpenShift Service Mesh 3.0

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: 8.7
EPSS: 0.38%
CISA KEV: Not listed
Published: 2026.03.11

PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability0.38%

Technical severityCVSS 8.7

Vulnerability overview

Affected product and versions

Product: istio istio, Red Hat OpenShift AI 2.25, Red Hat OpenShift Service Mesh 3.0
Affected versions: >= >= 1.29.0-alpha.0, < 1.29.1, >= >= 1.28.0-alpha.0, < 1.28.5, >= < 1.27.8, < 1.27.8, >= 1.28.0 < 1.28.5, >= 1.29.0 < 1.29.1
Fixed versions: 1.27.8, 1.28.5, 1.29.1

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that istio istio, Red Hat OpenShift AI 2.25, Red Hat OpenShift Service Mesh 3.0 and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CWE: CWE-1392, CWE-200