CVE-2021-31920

mediumpriority · track · 26OT risk · elevatedEPSS 0.013 · 71 %ileEUUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
1.32% (71st) EPSS
CVSS 4 · medium
Is it mine?
64 products
Check your exposure
Who says so?
5 sources
cnnvd · enisa_euvd · nvd · osv

EPSS · scored 2026-10-27

Istio before 1.8.6 and 1.9.x before 1.9.5 has a remotely exploitable vulnerability where an HTTP request path with multiple slashes or escaped slash characters (%2F or %5C) could potentially bypass an Istio authorization policy when path based authorization rules are used.

01

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

02

cvss

Technical severity, 0–10. One row per scoring source.

8.1
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 4–8.1

v2.04mediumAV:N/AC:L/Au:S/C:P/I:N/A:Nprimary · NVD / NIST USexploitability 8 · impact 2.9
v3.16.5mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:Nprimary · NVD / NIST USexploitability 2.8 · impact 3.6
v3.16.5mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:Nsecondary · OSV
v3.16mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:Usecondary · CVSS-BT (t0sche)
v3.18.1highCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Nsecondary · Red Hat Product Security US
03

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-706USprimaryCWE-863USCWE-863US
04

affected products (64)

Products and version ranges known to be affected.

showing 20 of 64
05

advisories (3)

Vendor and ecosystem advisories describing this.

  • RHSA-2021:1538Red Hat Security Advisory: Red Hat OpenShift Service Mesh 2.0.4 security update2021-05-11csaf · redhat_csafUS

    An update for servicemesh and servicemesh-proxy is now available for OpenShift Service Mesh 2.0. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

  • RHSA-2021:1540Red Hat Security Advisory: Red Hat OpenShift Service Mesh 1.1.14 security update2021-05-11csaf · redhat_csafUS

    An update for servicemesh and servicemesh-proxy is now available for OpenShift Service Mesh 1.1. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

  • GHSA-6q5m-22mq-q2xvIstio Authorization Bypass Vulnerability2022-05-24ghsa · osvUS

    Istio before 1.8.6 and 1.9.x before 1.9.5 has a remotely exploitable vulnerability where an HTTP request path with multiple slashes or escaped slash characters (%2F or %5C) could potentially bypass an Istio authorization policy when path based authorization rules are used.

06

also known as (3)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

cnnvdenisa_euvdnvdosvredhat_csafNVDCVE.orgMITRE
published 2021-05-27modified 2026-06-17
09

references (9)

External citations — patches, advisories, analysis.

scry

Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.

Free scan