CVE-2023-53921: SitemagicCMS 4.4.3 contains a remote code execution vulnerability that allows attackers to upload malicious PH

This week

CRITICAL 9.8REMOTEDOWNGRADE

CVE-2023-53921 is a critical-severity flaw (CVSS 9.8) affecting sitemagic cms. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

SitemagicCMS 4.4.3 contains a remote code execution vulnerability that allows attackers to upload malicious PHP files to the files/images directory. Attackers can upload a .phar file with system command execution payload to compromise the web application and execute arbitrary system commands.

Why this priority

Critical severity
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.0% (top 39%)
CISA exploited list	No
Weakness	CWE-434
Published	2025-12-17
Last modified	2026-06-17

Publisher (CNA): VulnCheck · Vendor: sitemagic

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

Am I affected?

Timeline

2025-12-17 23:15 UTCPublished CVE record published
2026-06-17 06:46 UTCUpdated Record last modified

sitemagic sitemagic cms DOWNGRADE

Affected: 4.4.3

Fixed in: no fixed release known

Safe to downgrade to: a release before 4.4.3

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 4.4.3 (Debian / Ubuntu)

apt-cache madison sitemagic-cms sudo apt install sitemagic-cms=<VERSION_BEFORE_4.4.3> sudo apt-mark hold sitemagic-cms

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

dnf --showduplicates list sitemagic-cms sudo dnf downgrade sitemagic-cms-<VERSION_BEFORE_4.4.3> sudo dnf versionlock add sitemagic-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.

Exact fixes by distribution

A distro patch exists: prefer upgrading over downgrading.

Fedora 46 · conan · FIXED · 2.31.0-1.fc46 · FEDORA-2026-ba58084ab5 · source

sudo dnf upgrade --advisory=FEDORA-2026-ba58084ab5

Fedora ELN · tesseract · FIXED · 5.5.4-1.eln159 · FEDORA-2026-866cf60ee6 · source

sudo dnf upgrade --advisory=FEDORA-2026-866cf60ee6

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Write-up: www.exploit-db.com/exploits/51464

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-2023-53921?

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

Is CVE-2023-53921 being exploited?

CVE-2023-53921 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-2023-53921 affect?

CVE-2023-53921 affects sitemagic cms. Severity is critical (CVSS 9.8). SitemagicCMS 4.4.3 contains a remote code execution vulnerability that allows attackers to upload malicious PHP files to the files/images directory. Attackers can upload a .phar file with system command execution payload to compromise the w

How urgent is CVE-2023-53921?

Priority 60/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action

Software pages

PHP vulnerabilities

References

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