CVE-2023-53923: UliCMS 2023.1 contains a privilege escalation vulnerability that allows unauthenticated attackers to create ad

This week

CRITICAL 9.8REMOTEDOWNGRADE

CVE-2023-53923 is a critical-severity flaw (CVSS 9.8) affecting ulicms. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

UliCMS 2023.1 contains a privilege escalation vulnerability that allows unauthenticated attackers to create administrative accounts through the UserController endpoint. Attackers can send a crafted POST request to /dist/admin/index.php with specific parameters to generate a new admin user with full system access.

Why this priority

Critical severity
Public exploit reference
CISA SSVC: automatable with total technical impact
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	0.6% (top 54%)
CISA exploited list	No
Weakness	CWE-862
Published	2025-12-17
Last modified	2026-06-17

Publisher (CNA): VulnCheck · Vendor: ulicms

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

ulicms ulicms DOWNGRADE

Affected: 2023.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 2023.1

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 2023.1 (Debian / Ubuntu)

apt-cache madison ulicms sudo apt install ulicms=<VERSION_BEFORE_2023.1> sudo apt-mark hold ulicms

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

dnf --showduplicates list ulicms sudo dnf downgrade ulicms-<VERSION_BEFORE_2023.1> sudo dnf versionlock add ulicms

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 ELN · openjpeg · FIXED · 2.5.4-5.eln159 · FEDORA-2026-1a5f60f401 · source

sudo dnf upgrade --advisory=FEDORA-2026-1a5f60f401

Fedora 46 · trustedqsl · FIXED · 2.8.7-1.fc46 · FEDORA-2026-6b1bc90ebc · source

sudo dnf upgrade --advisory=FEDORA-2026-6b1bc90ebc

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/51433

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-2023-53923?

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

Is CVE-2023-53923 being exploited?

CVE-2023-53923 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-2023-53923 affect?

CVE-2023-53923 affects ulicms. Severity is critical (CVSS 9.8). UliCMS 2023.1 contains a privilege escalation vulnerability that allows unauthenticated attackers to create administrative accounts through the UserController endpoint. Attackers can send a crafted POST request to /dist/admin/index.php with

How urgent is CVE-2023-53923?

Priority 59/100. Critical severity; Public exploit reference; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action

Software pages

PHP vulnerabilities

Related CVEs

CVE-2023-53925 MEDIUM 6.1 DOWNGRADE UliCMS 2023.1 contains a stored cross-site scripting vulnerability that allows attackers to upload malicious S
CVE-2023-53924 HIGH 8.8 DOWNGRADE UliCMS 2023.1-sniffing-vicuna contains a remote code execution vulnerability that allows authenticated attacke
CVE-2023-53914 CRITICAL 9.8 DOWNGRADE UliCMS 2023.1 contains an authentication bypass vulnerability that allows unauthenticated attackers to create

References

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