CVE-2026-40521
8.8 · HIGHOverview
CVE-2026-40521 is a high-severity vulnerability. It was published on June 29, 2026 and has a CVSS 3.1 base score of 8.8 (HIGH).
This vulnerability has a CVSS 3.1 base score of 8.8, rated HIGH. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
Technical Description
FrontAccounting before 2.4.20 contains a path traversal vulnerability in the attachment upload handler that allows authenticated attackers to execute arbitrary code by uploading files with traversal sequences in the unique_name parameter. Attackers can supply path traversal sequences ../../../shell.php to write files outside the intended attachments directory into the web root, and by uploading PHP files without extension validation, achieve remote code execution as the web server user.
Remediation
Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
References
Frequently Asked Questions
What is CVE-2026-40521?
CVE-2026-40521 is a high-severity vulnerability. It was published on June 29, 2026 and has a CVSS 3.1 base score of 8.8 (HIGH).
How severe is CVE-2026-40521?
This vulnerability has a CVSS 3.1 base score of 8.8, rated HIGH. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
How do I fix or remediate CVE-2026-40521?
Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-40521?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-40521 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
Automated penetration testing that runs continuously, not just quarterly.
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Browser-based exploitation validates findings with real proof-of-concept.
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