How severe is CVE-2021-20206?

CVE-2021-20206 has a CVSS score of 7.2/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2021-20206?

CVE-2021-20206 affects the following packages: github.com/containernetworking/cni (Go). Ecosystems affected: Go.

How do I fix CVE-2021-20206?

Update github.com/containernetworking/cni to 0.8.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-20206 is resolved across your whole dependency graph.

How do I detect CVE-2021-20206 in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/containernetworking/cni, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2021-20206 if there is no patch (or I can't update yet)?

Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.

Is CVE-2021-20206 actively exploited in the wild?

No public exploit code has been indexed for CVE-2021-20206 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2021-20206?

CVE-2021-20206 has an EPSS (Exploit Prediction Scoring System) score of 1.5%, placing it in the 74th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2021-20206?

CVE-2021-20206 is classified as Improper Input Validation (CWE-20), Path Traversal (CWE-22). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2021-20206 published, and has it been updated?

CVE-2021-20206 was published on March 26, 2021 and was last updated on July 9, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹

🐹 Go

Not in CISA KEV

HIGH severity

CVE-2021-20206 — cni

HIGHFix: containernetworking/cni#808

CVE-2021-20206 is a high-severity (CVSS 7.2) Improper Input Validation vulnerability in github.com/containernetworking/cni. A fix is available for github.com/containernetworking/cni — see the affected versions and patch details below.

containernetworking/cni improper limitation of path name

Also known asGHSA-xjqr-g762-pxwpGO-2022-0230

Published

Mar 26, 2021

Updated

Jul 9, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 10, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

1.5%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs74th percentile — riskier than 74% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2021-20206 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

1 pkg affected

🐹github.com/containernetworking/cni

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

An improper limitation of path name flaw was found in containernetworking/cni in versions before 0.8.1. When specifying the plugin to load in the 'type' field in the network configuration, it is possible to use special elements such as "../" separators to reference binaries elsewhere on the system. This flaw allows an attacker to execute other existing binaries other than the cni plugins/types, such as 'reboot'. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.

Specific Go Packages Affected

github.com/containernetworking/cni/pkg/invoke

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/containernetworking/cni`	all versions	0.8.1`go get github.com/containernetworking/cni@v0.8.1`

Affected Products

1 product · 1 configurations

Application

container network interfacelinuxfoundation

< 0.8.1

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/containernetworking/cni, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/containernetworking/cni to 0.8.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-20206 is resolved across your whole dependency graph.
Workarounds
Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate

OpenShift ServiceMesh (OSSM) does package a vulnerable version of containernetworking/cni, however, the NetworkDefinitionAttachment is defined in code and cannot be easily changed except through a user who has access to the operator namespace such as cluster-admin. As such, for OSSM, the impact is Moderate. The fix…

Product	Fixed in	Advisory
Red Hat OpenShift Container Platform 4.7	`openshift4/ose-docker-builder:v4.7.0-202103270130.p0`	RHSA-2021:1005
Red Hat OpenShift Container Platform 4.7	`openshift4/ose-sriov-cni:v4.7.0-202103270130.p0`	RHSA-2021:1007
Red Hat OpenShift Container Platform 4.7	`openshift4/ose-sriov-infiniband-cni:v4.7.0-202104281843.p0`	RHSA-2021:1552
Red Hat OpenShift Container Platform 4.7	`openshift4/ose-container-networking-plugins-rhel8:v4.7.0-202201261537.p0.ga3cf46b.assembly.stream`	RHSA-2022:0492
Red Hat OpenShift Container Platform 4.7	`openshift4-wincw/windows-machine-config-rhel8-operator:2.0.5-4`	RHSA-2022:1660
Red Hat OpenShift Container Platform 4.8	`openshift4/ose-container-networking-plugins-rhel8:v4.8.0-202106291913.p0.git.a8801b0.assembly.stream`	RHSA-2021:2438
Red Hat OpenShift Container Platform 4.8	`openshift4-wincw/windows-machine-config-rhel8-operator:3.0.0-16`	RHSA-2021:3001

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2021-20206 in your dependencies?

Find it across Go, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

7.2/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

High

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Raw vector

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

CWE Classification

CWE-20Improper Input Validation CWE-22Path Traversal

Weaponization

No known public exploit tooling found.

OpenSSF Scorecard

Package health score

cni

4.6/10

Branch-ProtectionN/A

Code-Review10/10

Dependency-Update-Tool10/10

Maintained1/10

Vulnerabilities0/10

Assessed Aug 30, 2026

Timeline

Disclosed

Mar 26, 2021

Last updated

Jul 9, 2026

Identifiers

CVE-2021-20206

GHSA-xjqr-g762-pxwp

GO-2022-0230

References

Advisorysnyk.io Advisorynvd.nist.gov Reportbugzilla.redhat.com Webgithub.com Webpkg.go.dev Packagegithub.com

Related vulnerabilities

This CVE is high severity; 2 of 8 other CVEs with CWE-20 are rated as high or higher (top: high).

CVE-2026-61794CVE-2026-81875CVE-2026-81876CVE-2026-61793GHSA-2xmm-m4wv-3fjhCVE-2026-56831CVE-2026-54529GHSA-cc9r-2j5m-2m83Browse all CWE-20

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedJul 9, 2026

CVE-2021-20206 — cni

EPSS Exploitation Probability

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

Description

Specific Go Packages Affected

Affected Packages

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

Fixing This On Your OS

Frequently Asked Questions

Is CVE-2021-20206 in your dependencies?