How severe is CVE-2021-47735?

CVE-2021-47735 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-47735 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (51st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-47735?

CVE-2021-47735 affects Cmsimple. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-47735?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2021-47735 have an EU (EUVD) identifier?

Yes. CVE-2021-47735 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-204828.

When was CVE-2021-47735 published?

CVE-2021-47735 was published on 2025-12-23 and last updated on 2026-06-17.

CVE-2021-47735

CVE-2021-47735 is a high-severity vulnerability in Cmsimple with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-94.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v4: 8.6
EPSS exploit prediction: 1% (51st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-204828
Weakness: CWE-94
Affected product: Cmsimple
Published: 2025-12-23
Last modified: 2026-06-17

Description

CMSimple 5.4 contains an authenticated remote code execution vulnerability that allows logged-in attackers to inject malicious PHP code into template files. Attackers can exploit the template editing functionality by crafting a reverse shell payload and saving it through the template editing endpoint with a valid CSRF token.

Frequently asked questions

What is CVE-2021-47735?: CMSimple 5.4 contains an authenticated remote code execution vulnerability that allows logged-in attackers to inject malicious PHP code into template files. Attackers can exploit the template editing functionality by crafting a reverse shell payload and saving it through the template editing endpoint with a valid CSRF token.
How severe is CVE-2021-47735?: CVE-2021-47735 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-47735 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (51st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-47735?: CVE-2021-47735 affects Cmsimple. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-47735?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2021-47735 have an EU (EUVD) identifier?: Yes. CVE-2021-47735 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-204828.
When was CVE-2021-47735 published?: CVE-2021-47735 was published on 2025-12-23 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:cmsimple:cmsimple:5.4:*:*:*:*:*:*:*

More vulnerabilities in Cmsimple

CVE-2021-43741 — Critical (CVSS 9.8): CMSimple 5.4 is vulnerable to Directory Traversal. The vulnerability exists when a user changes the file name to…
CVE-2024-57548 — Critical (CVSS 9.1): CMSimple 5.16 allows the user to edit log.php file via print page.
CVE-2024-58280 — High (CVSS 8.8): CMSimple 5.15 contains a remote command execution vulnerability that allows authenticated attackers to modify file…
CVE-2021-47734 — High (CVSS 7.8): CMSimple 5.4 contains an authenticated local file inclusion vulnerability that allows remote attackers to manipulate…
CVE-2024-57549 — High (CVSS 7.5): CMSimple 5.16 allows the user to read cms source code through manipulation of the file name in the file parameter of a…
CVE-2024-57547 — High (CVSS 7.5): Insecure Permissions vulnerability in CMSimple v.5.16 allows a remote attacker to obtain sensitive information via a…

All CVEs affecting Cmsimple →

Other CWE-94 (Code Injection) vulnerabilities

CVE-2026-57624 — Critical (CVSS 10.0): Unauthenticated Remote Code Execution (RCE) in Blocksy Companion Pro <= 2.1.46 versions.
CVE-2026-10134 — Critical (CVSS 10.0): IBM Langflow OSS 1.0.0 through 1.9.3 allows an attacker to read every secret available to the Langflow process, read…
CVE-2026-53576 — Critical (CVSS 10.0): Kestra is an open-source, event-driven orchestration platform. Prior to 1.0.45 and 1.3.21, the authentication filter…
CVE-2026-10561 — Critical (CVSS 10.0): IBM Langflow OSS 1.0.0 through 1.9.3 has an vulnerability due to an improper isolation of Python execution combined…
CVE-2026-25470 — Critical (CVSS 10.0): Improper Control of Generation of Code ('Code Injection') vulnerability in ACPT ACPT (Pro) - Custom Post Types Plugin…
CVE-2026-48836 — Critical (CVSS 10.0): Unauthenticated Remote Code Execution (RCE) in Easy Invoice <= 2.1.19 versions.

Browse all CWE-94 (Code Injection) vulnerabilities →