CVE-2021-42227: Cross SIte Scripting (XSS) vulnerability exists in KindEditor 4.1.x via a Google search inurl:/examples/upload

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MEDIUM 6.1UPGRADE

CVE-2021-42227 is a medium-severity flaw (CVSS 6.1) affecting kindeditor. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Cross SIte Scripting (XSS) vulnerability exists in KindEditor 4.1.x via a Google search inurl:/examples/uploadbutton.html and then the .html file on the website that uses this editor (the file suffix is allowed).

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	6.1 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.9% (top 39%)
CISA exploited list	No
Weakness	CWE-79
Published	2021-10-14
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: kindsoft

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-10-14 17:15 UTCPublished CVE record published
2026-06-17 04:09 UTCUpdated Record last modified

kindsoft kindeditor UPGRADE

Affected: >= 4.1 and <= 4.1.12

Fixed in: newer than 4.1.12

Safe to downgrade to: a release before 4.1

1. Check installed version

apt-cache policy kindeditor || rpm -q kindeditor || kindeditor --version

2. UPGRADE to newer than 4.1.12 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade kindeditor

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade kindeditor

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 4.1 (Debian / Ubuntu)

apt-cache madison kindeditor sudo apt install kindeditor=<VERSION_BEFORE_4.1> sudo apt-mark hold kindeditor

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list kindeditor sudo dnf downgrade kindeditor-<VERSION_BEFORE_4.1> sudo dnf versionlock add kindeditor

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2021-42227?

kindeditor: upgrade to newer than 4.1.12. Exact commands for each OS are on this page.

Is CVE-2021-42227 being exploited?

CVE-2021-42227 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2021-42227 affect?

CVE-2021-42227 affects kindeditor. Severity is medium (CVSS 6.1). Cross SIte Scripting (XSS) vulnerability exists in KindEditor 4.1.x via a Google search inurl:/examples/uploadbutton.html and then the .html file on the website that uses this editor (the file suffix is allowed).

How urgent is CVE-2021-42227?

Priority 42/100. Public exploit reference

Related CVEs

CVE-2021-42228 HIGH 8.8 UPGRADE A Cross Site Request Forgery (CSRF) vulnerability exists in KindEditor 4.1.x, as demonstrated by examples/uplo
CVE-2021-37267 MEDIUM 6.1 MITIGATE Cross Site Scripting (XSS) vulnerability exists in all versions of KindEditor, which can be exploited by an at
CVE-2021-30086 MEDIUM 6.1 DOWNGRADE Cross Site Scripting (XSS) vulnerability exists in KindEditor (Chinese versions) 4.1.12, which can be exploite
CVE-2020-28717 MEDIUM 6.1 DOWNGRADE Cross Site Scripting (XSS) vulnerability in content1 parameter in demo.jsp in kindsoft kindeditor version 4.1.
CVE-2019-7543 MEDIUM 6.1 DOWNGRADE In KindEditor 4.1.11, the php/demo.php content1 parameter has a reflected Cross-site Scripting (XSS) vulnerabi

References

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