CVE-2024-40521: SeaCMS 12.9 has a remote code execution vulnerability

This month

HIGH 8.8DOWNGRADE

CVE-2024-40521 is a high-severity flaw (CVSS 8.8) affecting seacms. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

SeaCMS 12.9 has a remote code execution vulnerability. The vulnerability is due to the fact that although admin_template.php imposes certain restrictions on the edited file, attackers can still bypass the restrictions and write code in some way, allowing authenticated attackers to exploit the vulnerability to execute arbitrary commands and gain system privileges.

Why this priority

High severity
Public exploit reference

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

Risk facts

CVSS score	8.8 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	1.3% (top 30%)
CISA exploited list	No
Weakness	CWE-94
Published	2024-07-12
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: seacms

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

Am I affected?

Timeline

2024-07-12 16:15 UTCPublished CVE record published
2026-06-17 07:46 UTCUpdated Record last modified

seacms seacms DOWNGRADE

Affected: 12.9

Fixed in: no fixed release known

Safe to downgrade to: a release before 12.9

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 12.9 (Debian / Ubuntu)

apt-cache madison seacms sudo apt install seacms=<VERSION_BEFORE_12.9> sudo apt-mark hold seacms

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

dnf --showduplicates list seacms sudo dnf downgrade seacms-<VERSION_BEFORE_12.9> sudo dnf versionlock add seacms

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-2024-40521?

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

Is CVE-2024-40521 being exploited?

CVE-2024-40521 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-2024-40521 affect?

CVE-2024-40521 affects seacms. Severity is high (CVSS 8.8). SeaCMS 12.9 has a remote code execution vulnerability. The vulnerability is due to the fact that although admin_template.php imposes certain restrictions on the edited file, attackers can still bypass the restrictions and write code in some

How urgent is CVE-2024-40521?

Priority 53/100. High severity; Public exploit reference

Software pages

PHP vulnerabilities

Related CVEs

CVE-2025-15003 MEDIUM 4.7 UPGRADE A vulnerability was found in SeaCMS up to 13.3
CVE-2025-10662 MEDIUM 4.7 UPGRADE A vulnerability has been found in SeaCMS up to 13.3
CVE-2025-11071 MEDIUM 4.7 DOWNGRADE A security vulnerability has been detected in SeaCMS 13.3.20250820
CVE-2025-50592 MEDIUM 5.4 UPGRADE Cross site scripting vulnerability in seacms before 13.2 via the vid parameter to Upload/js/player/dmplayer/pl
CVE-2025-25813 MEDIUM 5.1 DOWNGRADE SeaCMS v13.3 was discovered to contain a remote code execution (RCE) vulnerability via the component admin_fil

References

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