CVE-2021-47860Public exploitNetwork attack vector

Server code execution via forged plugin settings

Published Jan 21, 2026 · Updated Jan 21, 2026

Cross-site request forgery in GetSimple CMS Custom JS Plugin 0.1 allows remote attackers to execute code on the hosting server. The CustomJSPlugin settings handler accepts a cross-origin POST without a CSRF token, stores customjs_js_content, and emits that JavaScript in the theme footer; the payload then uses the administrator's session and theme editor to write a PHP web shell. Exploitation requires an authenticated administrator to visit the attacker's page and then load a CMS page, after which the stored script can act with that session's privileges.

CVSS severity8.5
High
EPSS probability0.24%
Next 30 days · Sep 17, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site request forgery in GetSimple CMS Custom JS Plugin 0.1 allows remote attackers to execute code on the hosting server. The CustomJSPlugin settings handler accepts a cross-origin POST without a CSRF token, stores customjs_js_content, and emits that JavaScript in the theme footer; the payload then uses the administrator's session and theme editor to write a PHP web shell. Exploitation requires an authenticated administrator to visit the attacker's page and then load a CMS page, after which the stored script can act with that session's privileges.

The record

CVE
CVE-2021-47860
Published
Jan 21, 2026
Updated
Jan 21, 2026
Vendor
GetSimple CMS
Product
Custom JS Plugin
Classifications
CWE-352, CAPEC-62, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 21, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 21, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

GetSimple CMS · Custom JS Pluginversion=0.1

Published CVSS scores

9.6Researcher disclosureCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
4.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
8.5VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
5.3VulnCheckCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-352Cross-Site Request Forgery (CSRF)
CAPEC-62Cross Site Request Forgery
T1189Drive-by Compromise

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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