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Atomicorp WAF Research Note: CVE-2026-55634

Pimcore: Remote Code Execution via DataObject Class-Definition Field Name

CVE Details

Status: Attack Blocked by Atomicorp

Vulnerability Description

Pimcore is an Open Source Data & Experience Management Platform. Prior to 11.5.19, 12.3.10, and 2026.1.6, the class-definition import endpoint /pimcore-studio/api/class/definition/configuration-view/detail/{id}/import accepts a DataObject field name that is emitted without an identifier allowlist by lib/DataObject/ClassBuilder/FieldDefinitionPropertiesBuilder.php into generated PHP properties and by models/DataObject/ClassDefinition/Helper/Dao.php into ALTER TABLE identifiers. An authenticated user with the objects permission can inject PHP syntax into the generated DataObject class, causing attacker-controlled code in generated var/classes/DataObject/.php files to run when an object of that class is instantiated, and can also inject SQL identifier content into schema-changing statements. The central models/DataObject/ClassDefinition/Data.php::setName() validation did not reject semicolons, braces, backticks, spaces, or other non-identifier characters. This issue is fixed in versions 11.5.19, 12.3.10, and 2026.1.6.

  1. Maintain the observed Atomicorp protections. Keep your Atomicorp commercial rules current and confirm that the selected observed rules (340014 , 340029 , 344360 , 344361 , 344363 , 344364 , 344366 , 344370 , 393655 ) have not been locally disabled. Atomicorp commercial rules are enabled by default. If you use Atomic WAF, review the applicable policy and rule settings.

  2. Apply the vendor’s remediation. WAF protection is defense in depth and does not replace upgrading or following the affected vendor’s guidance.

    • Affected versions: pimcore version < 11.5.19.
    • Affected versions: pimcore version >= 12.0.0-RC1, < 12.3.10.
    • Affected versions: pimcore version >= 2026.1.0, < 2026.1.6.
    • No specific CNA/vendor solution or workaround is included in the current CVE Record . Review the vendor’s security advisories and supported-release guidance before making changes.

  3. Validate after changes. Confirm rule updates are current, review WAF events for the affected application, and test application behavior after vendor upgrades, mitigations, or local policy changes.

Research Notes

Atomicorp WAF protections are designed around attack techniques and exploit behaviors, allowing existing protections to apply across multiple vulnerabilities without requiring a unique rule for every CVE.

Public Vulnerability References

Test or Research Source

  • Source: Atomicorp AI Research Framework
  • Tags: cve, derived, rce, waf-probe

Research Note Context

This research note documents exploit-technique analysis associated with this vulnerability and references Atomicorp WAF protections observed during engineering review, testing, or validation activities.

Atomicorp security controls are generally designed to identify and mitigate attack techniques and exploit behaviors rather than individual CVE identifiers. As a result, protections developed for one vulnerability may also apply to related attack variants and future vulnerabilities using similar techniques.

Learn More

Atomicorp develops commercially supported security technologies for web applications, servers, endpoints, workloads, and legacy enterprise platforms.

Organizations interested in protecting systems against exploit techniques associated with vulnerabilities such as this one can learn more about:

  • Atomic ModSecurity Rules: commercially maintained WAF rules for ModSecurity deployments, including protections for web attacks, bots, scanners, malware, exploitation attempts, and emerging vulnerability classes.
  • Atomic WAF: an enterprise web application firewall with Atomicorp rules, centralized management, reporting, authentication controls, and operational tooling.
  • Atomic ModSecurity Integrator: a special licensing option for MSPs, MSSPs, OEMs, VARs, reverse proxy providers, and other integrators who want to incorporate Atomicorp ModSecurity rule technology into their own products or services.
  • Atomic OSSEC: an enterprise OSSEC-based intrusion detection, compliance, and security monitoring platform.
  • Atomic Protector: workload protection for Linux, web, cloud, data center, and hybrid environments.

For additional information, product evaluations, or technical discussions, visit https://www.atomicorp.com/ or https://modsecurity.io/ .