PatchSiren

PatchSiren cyber security CVE debrief

CVE-2026-70553 MaxSite CVE debrief

AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-08-04T20:16:56.023Z and has not been modified since then. CVE-2026-70553 is a critical vulnerability in MaxSite CMS with a CVSS score of 9.3, allowing unauthenticated remote code execution. The vulnerability is caused by improper handling of user input in the install endpoint, which can be exploited by submitting crafted POST requests. This allows attackers to inject arbitrary PHP code into the application configuration file, resulting in persistent unauthenticated remote code execution as the web-server process user. Administrators and users of MaxSite CMS, as well as security teams and IT professionals responsible for maintaining and securing web applications, should be aware of this critical vulnerability and take immediate action to assess and mitigate potential risks.

Vendor
MaxSite
Product
MaxSite CMS
CVSS
CRITICAL 9.3
CISA KEV
Not listed in stored evidence
Original CVE published
2026-08-04
Original CVE updated
2026-08-31
Advisory published
2026-08-04
Advisory updated
2026-08-31

Who should care

Administrators and users of MaxSite CMS, as well as security teams and IT professionals responsible for maintaining and securing web applications, should be aware of this critical vulnerability and take immediate action to assess and mitigate potential risks.

Technical summary

The MaxSite CMS contains a remote code execution vulnerability that allows unauthenticated attackers to inject arbitrary PHP code into the application configuration file. This is achieved by submitting crafted POST requests to the install endpoint after installation is complete. The vulnerability can be exploited by supplying a malicious db_dbprefix value containing a single quote to break out of a PHP string literal in application/config/database.php, appending attacker-controlled PHP statements that are executed by the web server on every subsequent request, resulting in persistent unauthenticated remote code execution as the web-server process user.

Defensive priority

CVE-2026-70553 is a critical vulnerability in MaxSite CMS with a CVSS score of 9.3, allowing unauthenticated remote code execution. Immediate attention is required to assess and mitigate potential risks.

Recommended defensive actions

  • Review and assess the MaxSite CMS installation for potential exposure
  • Apply patches or updates to fix the vulnerability
  • Implement additional security measures to detect and prevent similar attacks
  • Monitor the system for suspicious activity
  • Consider compensating controls to mitigate potential risks

Evidence notes

The CVE description indicates that MaxSite CMS contains a remote code execution vulnerability allowing unauthenticated attackers to inject arbitrary PHP code. The vulnerability is caused by improper handling of user input in the install endpoint, which can be exploited by submitting crafted POST requests. The CVSS score of 9.3 indicates a critical vulnerability.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-70553 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-70553

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-70553 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-70553

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.