CVE-2026-3395Public exploitNetwork attack vector

Unauthenticated code execution via preview shortcode evaluation

Published Mar 1, 2026 · Updated Mar 1, 2026

Code injection in MaxSite CMS 109.0 through 109.1 allows remote attackers to execute PHP code through the MarkItUp Preview AJAX endpoint. The handler passes the POST data field through content hooks without authentication, and the enabled run_php plugin evaluates PHP shortcode contents with eval(). Exploitation requires the run_php plugin to be enabled and permits commands to run with the web server process's privileges.

CVSS severity7.3
High
EPSS probability3.88%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Code injection in MaxSite CMS 109.0 through 109.1 allows remote attackers to execute PHP code through the MarkItUp Preview AJAX endpoint. The handler passes the POST data field through content hooks without authentication, and the enabled run_php plugin evaluates PHP shortcode contents with eval(). Exploitation requires the run_php plugin to be enabled and permits commands to run with the web server process's privileges.

The record

CVE
CVE-2026-3395
Published
Mar 1, 2026
Updated
Mar 1, 2026
Vendor
MaxSite
Product
MaxSite CMS
Classifications
CWE-94, CWE-74, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 1, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 1, 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=109.0
  2. Affected versionversion=109.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

MaxSite · MaxSite CMSversion=109.0; version=109.1

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5VulDBAV:N/AC:L/Au:N/C:P/I:P/A:P
7.3VulDBCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
5.5VulDBCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-94Improper Control of Generation of Code ('Code Injection')
CWE-74Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
T1190Exploit Public-Facing Application

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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