CVE-2021-39426

CRITICALNVD 9.89.8—

9.8

An issue was discovered in /Upload/admin/admin_notify.php in Seacms 11.4 allows attackers to execute arbitrary php code via the notify1 parameter when the action parameter equals set.

CVSS v3: 9.8
EG Score: 9.8(medium)
EPSS: 61.3%
KEV: Not listed

Published

December 15, 2022

Last Modified

April 21, 2025

References (2)

cve@mitrehttps://github.com/seacms-com/seacms/issues/21
af854a3a-2127-422b-91ae-364da2661108https://github.com/seacms-com/seacms/issues/21

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

CWE-94Improper Control of Generation of Code (Code Injection)

Data Freshness Timeline

(refreshed 13× in last 7d / 20× in last 30d)

Every time one of our enrichment pipelines (NVD, MITRE cvelistV5, EPSS, CISA KEV, GHSA, OSV, vendor advisories) ran against this CVE. Most recent first.

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Frequently asked(5)

What is CVE-2021-39426?

CVE-2021-39426 is a critical vulnerability published on December 15, 2022. An issue was discovered in /Upload/admin/admin_notify.php in Seacms 11.4 allows attackers to execute arbitrary php code via the notify1 parameter when the action parameter equals set.

When was CVE-2021-39426 disclosed?

CVE-2021-39426 was first published in the National Vulnerability Database on December 15, 2022, with the most recent update on April 21, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2021-39426 actively exploited?

CVE-2021-39426 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 61.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2021-39426?

CVE-2021-39426 has a CVSS v3 base score of 9.8 (NVD).

How do I remediate CVE-2021-39426?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-39426, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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CVE-2021-39426

📅 Published

🔄 Last Modified

🔗 References (2)

Weakness Classification(1)

Data Freshness Timeline

❓ Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2021-39426?

🔗 Related CVEs(same CWE)

Same CWE

Published

Last Modified

References (2)

Frequently asked(5)

Related CVEs(same CWE)