CVE-2026-26351: GetSimpleCMS Community Edition (CE) versions prior to 3.3.22 (3.3.16 tested) contains a stored cross-site scri

Routine

MEDIUM 4.8UPGRADE

CVE-2026-26351 is a medium-severity flaw (CVSS 4.8) affecting getsimple cms. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

GetSimpleCMS Community Edition (CE) versions prior to 3.3.22 (3.3.16 tested) contains a stored cross-site scripting (XSS) vulnerability in the Theme to Components functionality within components.php. User-supplied input provided to the "slug" field of a component is stored without proper output encoding. While other fields are sanitized using safe_slash_html(), the slug parameter is written to XML and later rendered in the administrative interfac

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	4.8 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	High
User interaction	Required
EPSS exploit chance	0.3% (top 73%)
CISA exploited list	No
Weakness	CWE-79
Published	2026-02-24
Last modified	2026-07-14

Publisher (CNA): VulnCheck · Vendor: getsimple-ce

Last updated 2026-07-14 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-02-24 23:16 UTCPublished CVE record published
2026-07-14 19:16 UTCUpdated Record last modified

getsimple-ce getsimple cms UPGRADE

Affected: >= 3.3.16 and < 3.3.22

Fixed in: 3.3.22

Safe to downgrade to: a release before 3.3.16

1. Check installed version

apt-cache policy getsimple-cms || rpm -q getsimple-cms || getsimple-cms --version

2. UPGRADE to 3.3.22 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade getsimple-cms

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade getsimple-cms

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 3.3.16 (Debian / Ubuntu)

apt-cache madison getsimple-cms sudo apt install getsimple-cms=<VERSION_BEFORE_3.3.16> sudo apt-mark hold getsimple-cms

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

dnf --showduplicates list getsimple-cms sudo dnf downgrade getsimple-cms-<VERSION_BEFORE_3.3.16> sudo dnf versionlock add getsimple-cms

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-2026-26351?

getsimple cms: upgrade to 3.3.22. Exact commands for each OS are on this page.

Is CVE-2026-26351 being exploited?

CVE-2026-26351 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-2026-26351 affect?

CVE-2026-26351 affects getsimple cms. Severity is medium (CVSS 4.8). GetSimpleCMS Community Edition (CE) versions prior to 3.3.22 (3.3.16 tested) contains a stored cross-site scripting (XSS) vulnerability in the Theme to Components functionality within components.php. User-supplied input provided to the "slu

How urgent is CVE-2026-26351?

Priority 23/100. No elevated risk signals yet.

Software pages

PHP vulnerabilities

Related CVEs

CVE-2026-28495 CRITICAL 9.6 UPGRADE GetSimple CMS is a content management system
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CVE-2026-27147 MEDIUM 5.4 UPGRADE GetSimple CMS is a content management system
CVE-2026-27146 MEDIUM 4.5 UPGRADE GetSimple CMS is a content management system

References

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