CVE-2026-73613 filebrowser CVE debrief

Who should care

Defenders responsible for filebrowser deployments, particularly those with authenticated users having Create permission, should assess exposure and prioritize patching. This includes reviewing user permissions, monitoring filebrowser logs for suspicious activity, and ensuring that Create permission is restricted to only necessary users. Security teams should also consider potential data loss or integrity impacts if the vulnerability is exploited.

Why it matters

CVE-2026-73613 is a high-severity vulnerability in filebrowser that allows authenticated users with Create permission to delete arbitrary files outside their scope; defenders should verify and prioritize patching.

• Verification of filebrowser version and patching priority
• Restriction of Create permission to only necessary users
• Monitoring filebrowser logs for suspicious file deletion activity
• Potential data loss or integrity impact if exploited

Technical summary

The vulnerability exists in filebrowser versions before 2.63.19; an out-of-scope file deletion vulnerability in the TUS upload cache eviction mechanism allows authenticated users with only Create permission to delete arbitrary files outside their scope by swapping an ancestor directory with a symlink during the cache TTL window, bypassing ScopedFs scope guards and Perm.Delete checks. This allows attackers to potentially delete arbitrary files outside their scope, impacting data integrity and confidentiality. Defenders should verify and prioritize patching.

Defensive priority

Authenticated users with Create permission may be able to delete arbitrary files outside their scope; defenders should verify and prioritize patching.

Recommended defensive actions

• Verify filebrowser version and prioritize patching to 2.63.19 or later
• Restrict Create permission to only necessary users
• Monitor filebrowser logs for suspicious file deletion activity
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The vulnerability exists in filebrowser versions before 2.63.19; an out-of-scope file deletion vulnerability in the TUS upload cache eviction mechanism allows authenticated users with only Create permission to delete arbitrary files outside their scope. Evidence is based on CVE Program and NVD sources; defenders should verify filebrowser versions and user permissions, noting potential limitations in source-provided information.

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.