CVE-2022-26352 is an unrestricted upload of file vulnerability in dotCMS dotCMS. CISA added it to the Known Exploited Vulnerabilities catalogue on 25 August 2022, which means attackers have used it in real attacks. Exploitation allows for remote code execution. Organisations running the affected product should apply the vendor fix or mitigation as a priority.
What this vulnerability means for dotCMS
An unrestricted file upload flaw in a web content platform is dangerous because uploaded content can be turned into executable server-side code or a foothold for further compromise. For remote code execution cases like this one, the upload path is not just a content handling issue, it becomes a direct server compromise path.
These flaws often matter most where the application accepts files from authenticated users, content editors, integrations, or public endpoints, because the trust boundary is weaker than it appears. The core question is whether the application validates the file’s type, content, location, and execution behaviour before storing it.
Why unrestricted upload becomes a compromise path
When file handling is weak, an attacker may be able to place a script, web shell, or other malicious payload where the application will process it. That can convert a routine upload feature into code execution, data access, or a launch point for lateral movement. The underlying weakness is not the file itself, but the missing control over what can be uploaded and how it can be handled afterward.
This kind of issue is especially dangerous in internet-facing products because the attack surface is easy to enumerate and the exploit path is often straightforward once the vulnerable endpoint is found. The impact is amplified when uploaded content inherits the application’s privileges or lands in a directory that can be interpreted by the web server.
How organisations check exposure and reduce risk
Exposure checks should begin with a complete asset inventory, then confirm whether dotCMS is deployed anywhere in the environment, whether those instances are reachable from the internet, and whether the vendor’s advisory or CISA KEV entry applies to them. If the application cannot be patched immediately, organisations should narrow upload access, restrict file types, isolate upload storage from executable paths, and review any content-processing pipeline that might transform a harmless-looking file into an executable one.
For prioritisation, treat this as a known-exploited vulnerability, not a theoretical weakness. The NIST National Vulnerability Database and the CVE Program remain the best authoritative references for record lookup and identification, while remediation details should come from the vendor advisory rather than from secondary summaries.
Detection, compromise review, and post-fix validation
Detection should focus on upload anomalies, unusual file extensions or MIME types, unexpected server-side execution in upload directories, and suspicious outbound activity after a new file appears. If exploitation is suspected, review the application’s logs, web server logs, and any related endpoint or host telemetry for signs that an uploaded file was executed or used to stage additional activity.
After remediation, validate that the upload path no longer accepts dangerous content, that stored files cannot execute, and that no web-accessible location can be used as a code staging area. If compromise occurred, investigate whether credentials, session material, API keys, or configuration secrets were accessed after the initial upload abuse.
Risk and Threat Considerations
This vulnerability can create direct remote code execution, which means the attacker’s first successful upload may be enough to move from application access to system-level control. In practice, that can expose data, enable persistence, and provide a platform for further intrusion.
Failure mechanism: The application accepts a file that is not sufficiently validated or segregated, then stores it where the server can interpret or execute it.
Impact: Attackers may run code on the host, drop additional tools, steal data, or use the compromised system as a pivot into the wider environment.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
OWASP ASVS and NIST SP 800-53 Rev 5 set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP ASVS | V5 — File Handling | Covers secure file upload validation and storage controls for this upload flaw |
| V16 — Security Logging and Error Handling | Supports detection and review of suspicious upload and execution activity | |
| Recommendation — Verify upload type, storage, and execution controls for every file-handling path. Log upload events and investigate anomalous file-processing or execution errors. | ||
| NIST SP 800-53 Rev 5 | SI-10 — Information Input Validation | Directly addresses validation failures that allow malicious file content into the system |
| SI-3 — Malicious Code Protection | Supports blocking malicious payloads delivered through uploaded files | |
| AU-6 — Audit Record Review, Analysis, and Reporting | Supports post-exploitation review of upload and execution evidence | |
| Recommendation — Apply input validation to reject unsafe upload content before it reaches processing. Scan uploaded content and block known malicious file payloads before use. Review upload and web execution logs for signs of abuse and compromise. | ||
Practitioner Guidance
Why practitioners should care: File upload issues are often treated as application hygiene problems, but this class of flaw can become a full server compromise when the uploaded object reaches an executable context. The practical priority is to remove any path from upload to execution, not just to block obvious malicious extensions.
What to watch for: A vulnerable upload feature that supports rich content, image handling, document conversion, or plugin-style extension points deserves immediate review, especially if it is internet-facing or used by less-trusted users. Those are the places where upload validation failures most often become exploitable.
Related resources from NHI Mgmt Group
- CVE-2021-20022 (SonicWall Email Security Unrestricted Upload of File)
- CVE-2021-26828 (OpenPLC ScadaBR Unrestricted Upload of File with Dangerous Type)
- CVE-2024-7694 (TeamT5 ThreatSonar Anti-Ransomware Unrestricted Upload of File with Dangerous Type)
- CVE-2025-52691 (SmarterTools SmarterMail Unrestricted Upload of File with Dangerous Type)
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Reviewed and updated by the NHIMG editorial team on October 17, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org