CVE-2026-73373 Joomla! Project CVE debrief

Who should care

Administrators and users of Joomla! Core versions 1.0.0-5.4.7 and 6.0.0-6.1.2 should be aware of this vulnerability and take necessary actions to protect their systems. This includes applying patches or updates provided by Joomla, restricting file uploads to only allow specific, safe file types, and monitoring servers for suspicious activity related to SHTML file execution. Additionally, organizations should consider implementing additional security measures such as Web Application Firewalls (WAFs) and review and update incident response plans to address potential code execution attacks. Security teams and vulnerability management teams should also be aware of this vulnerability and prioritize patching and mitigation efforts.

Technical summary

The vulnerability allows for unrestricted uploads of SHTML files in Joomla! Core versions 1.0.0-5.4.7 and 6.0.0-6.1.2. The default list of dangerous files did not include SHTML files, which could lead to code execution on servers that executed these files. This vulnerability has a high CVSS score of 8.9, indicating a significant risk. Organizations using Joomla! Core versions 1.0.0-5.4.7 and 6.0.0-6.1.2 should prioritize patching to prevent potential code execution.

Defensive priority

Organizations using Joomla! Core versions 1.0.0-5.4.7 and 6.0.0-6.1.2 should prioritize patching to prevent potential code execution.

Recommended defensive actions

• Apply patches or updates provided by Joomla to address the vulnerability
• Restrict file uploads to only allow specific, safe file types
• Monitor servers for suspicious activity related to SHTML file execution
• Consider implementing additional security measures such as Web Application Firewalls (WAFs)
• Review and update incident response plans to address potential code execution attacks

Evidence notes

The default list of dangerous files in Joomla! Core did not include SHTML files, which could lead to code execution on servers that executed these files. Affected versions include Joomla 1.0.0-5.4.7 and 6.0.0-6.1.2. The vulnerability allows for unrestricted uploads of SHTML files. The CVE record was published on 2026-08-18T16:18:17.173Z and has not been modified since then. The NVD entry is currently Analyzed. Administrators and users of Joomla! Core versions 1.0.0-5.4.7 and 6.0.0-6.1.2 should verify their systems and consider implementing additional security measures.

Sources and 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.