Grav has Unauthenticated Path Traversal & Arbitrary File Write in its FormFlash component — CVE-2026-42608

Summary

# Vulnerability Report: Grav CMS Unauthenticated Path Traversal & Arbitrary File Write **[ZERO-DAY] Unauthenticated Path Traversal leading to Arbitrary Directory Creation and Configuration Injection** ## Summary Grav CMS (v1.7.49.5 and latest development source) is vulnerable to a Zero-Day Path Traversal vulnerability within the FormFlash core component. By manipulating the session_id (passed as `__form-flash-id`…

Product

composer: getgrav/grav

What to do

General, cautious steps (verify details in the official source):

• Prioritize patching or mitigation immediately (treat as actively risky).
• Identify affected product versions in your inventory and verify whether you are impacted.
• Apply vendor patches/updates or recommended mitigations as soon as available.
• Read the official advisory for exact affected versions and remediation steps.

Official advisory

• Read the official source
• CVE Record
• NVD

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