Is CVE-2021-39156 actively exploited?

CVE-2021-39156 has no public evidence of in-the-wild exploitation as of 2024-11-21.

What is the CVSS score for CVE-2021-39156?

CVE-2021-39156 has a CVSS score of 8.1 (HIGH severity). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N.

How do I patch CVE-2021-39156?

Patch guidance is available from istio security advisories. CVEDatabase generates AI-assisted remediation guidance on demand for CVE-2021-39156.

Which products are affected by CVE-2021-39156?

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

Fix CVE-2021-39156 - HIGH istio istio

Description

Istio is an open source platform for providing a uniform way to integrate microservices, manage traffic flow across microservices, enforce policies and aggregate telemetry data. Istio 1.11.0, 1.10.3 and below, and 1.9.7 and below contain a remotely exploitable vulnerability where an HTTP request with `#fragment` in the path may bypass Istio’s URI path based authorization policies. Patches are available in Istio 1.11.1, Istio 1.10.4 and Istio 1.9.8. As a work around a Lua filter may be written to normalize the path.

CVSS Metrics

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
Attack Vector: network
Complexity: low
Privileges: none
User Action: required
Scope: unchanged
Confidentiality: high
Integrity: high
Availability: none
Weaknesses: CWE-863 · Incorrect Authorization CWE-706

Metadata

Primary Vendor: ISTIO
Published: 8/24/2021
Last Modified: 11/21/2024
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-2021-39156. CVEDatabase.com. Retrieved 1 May 2026. https://cvedatabase.com/cve/CVE-2021-39156

View on NIST NVD

CVE-2021-39156 vulnerability