CVE-2023-39343: Sulu is an open-source PHP content management system based on the Symfony framework

Routine

MEDIUM 4.3UPGRADE

CVE-2023-39343 is a medium-severity flaw (CVSS 4.3) affecting sulu. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Sulu is an open-source PHP content management system based on the Symfony framework. It allows over the Admin Login form to detect which user (username, email) exists and which one do not exist. Sulu Installation not using the old Symfony 5.4 security System and previous version are not impacted by this Security issue. The vulnerability has been patched in version 2.5.10.

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	4.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.6% (top 50%)
CISA exploited list	No
Weakness	CWE-204
Published	2023-08-04
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: sulu

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

Am I affected?

Timeline

2023-08-04 01:15 UTCPublished CVE record published
2026-06-17 06:12 UTCUpdated Record last modified

sulu sulu UPGRADE

Affected: >= 2.5.0 and < 2.5.10

Fixed in: 2.5.10

Safe to downgrade to: a release before 2.5.0

1. Check installed version

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

2. UPGRADE to 2.5.10 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade sulu

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 2.5.0 (Debian / Ubuntu)

apt-cache madison sulu sudo apt install sulu=<VERSION_BEFORE_2.5.0> sudo apt-mark hold sulu

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

dnf --showduplicates list sulu sudo dnf downgrade sulu-<VERSION_BEFORE_2.5.0> sudo dnf versionlock add sulu

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-2023-39343?

sulu: upgrade to 2.5.10. Exact commands for each OS are on this page.

Is CVE-2023-39343 being exploited?

CVE-2023-39343 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-2023-39343 affect?

CVE-2023-39343 affects sulu. Severity is medium (CVSS 4.3). Sulu is an open-source PHP content management system based on the Symfony framework. It allows over the Admin Login form to detect which user (username, email) exists and which one do not exist. Sulu Installation not using the old Symfony 5

How urgent is CVE-2023-39343?

Priority 27/100. No elevated risk signals yet.

Software pages

PHP vulnerabilities

Related CVEs

CVE-2024-47618 MEDIUM 5.4 UPGRADE Sulu is a PHP content management system
CVE-2024-47617 MEDIUM 6.1 DOWNGRADE Sulu is a PHP content management system
CVE-2024-27915 MEDIUM 6.8 UPGRADE Sulu is a PHP content management system

References

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