CVE-2021-47919: Simple CMS 2.1 contains a non-persistent cross-site scripting vulnerability in the preview.php file's id param

Routine

MEDIUM 6.4DOWNGRADE

CVE-2021-47919 is a medium-severity flaw (CVSS 6.4) affecting simple cms php. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Simple CMS 2.1 contains a non-persistent cross-site scripting vulnerability in the preview.php file's id parameter. Attackers can inject malicious script code through a GET request to execute arbitrary scripts and potentially hijack user sessions or perform phishing attacks.

Why this priority

Public exploit reference

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	6.4 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.3% (top 74%)
CISA exploited list	No
Weakness	CWE-79
Published	2026-02-01
Last modified	2026-06-17

Publisher (CNA): VulnCheck · Vendor: simplephpscripts

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

Am I affected?

Timeline

2026-02-01 13:15 UTCPublished CVE record published
2026-06-17 04:18 UTCUpdated Record last modified

simplephpscripts simple cms php DOWNGRADE

Affected: 2.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.1

1. Check installed version

apt-cache policy simple-cms-php || rpm -q simple-cms-php || simple-cms-php --version

2. No fixed release: DOWNGRADE to a release before 2.1 (Debian / Ubuntu)

apt-cache madison simple-cms-php sudo apt install simple-cms-php=<VERSION_BEFORE_2.1> sudo apt-mark hold simple-cms-php

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list simple-cms-php sudo dnf downgrade simple-cms-php-<VERSION_BEFORE_2.1> sudo dnf versionlock add simple-cms-php

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-2021-47919?

simple cms php: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2021-47919 being exploited?

CVE-2021-47919 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-2021-47919 affect?

CVE-2021-47919 affects simple cms php. Severity is medium (CVSS 6.4). Simple CMS 2.1 contains a non-persistent cross-site scripting vulnerability in the preview.php file's id parameter. Attackers can inject malicious script code through a GET request to execute arbitrary scripts and potentially hijack user se

How urgent is CVE-2021-47919?

Priority 34/100. Public exploit reference

Software pages

PHP vulnerabilities

Related CVEs

CVE-2021-47918 HIGH 8.1 DOWNGRADE Simple CMS 2.1 contains a remote SQL injection vulnerability that allows privileged attackers to inject unfilt
CVE-2021-47917 MEDIUM 6.4 DOWNGRADE Simple CMS 2.1 contains a persistent cross-site scripting vulnerability in user input parameters that allows r

References

← Back to latest CVEs