Is CVE-2026-31837 actively exploited?

CVE-2026-31837 has no public evidence of in-the-wild exploitation as of 2026-03-18.

What is the CVSS score for CVE-2026-31837?

CVE-2026-31837 has a CVSS score of 8.7 (HIGH severity). 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.

How do I patch CVE-2026-31837?

Patch guidance is available from istio security advisories. CVEDatabase generates AI-assisted remediation guidance on demand for CVE-2026-31837.

Which products are affected by CVE-2026-31837?

3 products: istio istio, istio istio, istio istio.

Fix CVE-2026-31837 - HIGH istio istio

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 Metrics

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
Attack Vector: network
Complexity: low
Privileges: none
User Action: none
Confidentiality: undefined
Integrity: undefined
Availability: undefined
Weaknesses: CWE-200 · Information Disclosure

Metadata

Primary Vendor: ISTIO
Published: 3/10/2026
Last Modified: 3/18/2026
Source: NIST NVD
Note: Verify all details with official vendor sources before applying patches.

Affected Products

istio : istioistio : istioistio : istio

Remediation Guidance

Executive Summary

Cite this page

CVE-2026-31837. CVEDatabase.com. Retrieved 1 May 2026. https://cvedatabase.com/cve/CVE-2026-31837

View on NIST NVD

CVE-2026-31837 vulnerability