Which versions of FileBrowser are affected by EUVD-2026-58650?

FileBrowser servers on Windows and similar case-insensitive filesystems are vulnerable to unauthorized cross-user file access and deletion through account takeover, exposing shared files to data…. A patch is available.

How to fix or mitigate EUVD-2026-58650?

Within 24 hours, identify all FileBrowser instances in your environment and verify their current version; if running versions before 2.63.19, apply the vendor-released patch immediately or disable public self-registration as an interim measure. Within 7 days, confirm patch deployment across all affected FileBrowser instances and validate that self-registration access controls are properly configured to restrict registration to authenticated users only, or disable if unnecessary. Within 30 days, conduct a forensic audit of FileBrowser file-access logs to detect any unauthorized cross-user file access, and notify affected users of potential exposure if evidence of exploitation is identified.

FileBrowser EUVD-2026-58650

Q: What is the CVSS score of EUVD-2026-58650?

EUVD-2026-58650 has a CVSS 4.0 base score of 9.2 (Critical). CVSS vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. EPSS exploitation probability: 0.3%.

| CVE-2026-72836 CRITICAL

Improper Handling of Case Sensitivity (CWE-178)

2026-08-14 VulnCheck

GHSA-f37p-wpgx-m9mr

Information Disclosure Microsoft Filebrowser

9.2

CVSS 4.0 · Vendor: VulnCheck

Severity by source

Vendor (VulnCheck) PRIMARY

9.2 CRITICAL

CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

vuln.today AI

8.1 HIGH

No account needed via self-signup (PR:N), but requires a case-insensitive FS plus enabled signup/CreateUserDir and a username-collision race (AC:H); full read/write/delete of victim files gives C:H/I:H/A:H.

3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

4.0 AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Primary rating from Vendor (VulnCheck).

CVSS VectorVendor: VulnCheck

CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Lifecycle Timeline

Source Code Evidence Fetched

Aug 14, 2026 - 12:24 vuln.today

Analysis Generated

Aug 14, 2026 - 12:24 vuln.today

CVE Published

Aug 14, 2026 - 11:35 cve.org

CRITICAL 9.2

DescriptionCVE.org

FileBrowser before 2.63.19 does not account for case-insensitive filesystems when checking home directory ownership during self-registration. When Signup and CreateUserDir are enabled and FileBrowser's root is on a case-insensitive filesystem (confirmed on Windows/NTFS), two self-registered usernames that differ only in letter case (e.g., CaseVictim and casevictim) are stored as distinct accounts but resolve to the same physical home directory, because the scope-ownership check compares the persisted scope as an exact case-sensitive string. A second registrant can therefore read, overwrite, and delete another account's files through authenticated HTTP endpoints, without needing an existing account or victim interaction.

AnalysisAI

Horizontal privilege escalation / cross-account file access in FileBrowser before 2.63.19 lets a self-registering user take over another user's files when the server runs on a case-insensitive filesystem (e.g. Windows/NTFS). …

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Vulnerability AssessmentAI

Exploitation	Exploitation requires the FileBrowser instance to have both Signup (self-registration) and CreateUserDir enabled, and its root directory to reside on a case-insensitive filesystem (confirmed Windows/NTFS). … Additional conditions and limiting factors are described in the full assessment.
Risk Assessment	This is a genuine, actionable authorization flaw rather than an inflated high-CVSS score, but its real-world reach is gated by configuration. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in.
Exploit Scenario	Full exploit scenario with step-by-step reproduction available after sign-in.
Remediation	Upgrade to FileBrowser 2.63.19 or later, which contains the vendor fix delivered in commit fe7efb2e6afe66774cd86a5b0a03033bd514d0c0 (see advisory GHSA-576v-w77m-gr84). … Detailed patch versions, workarounds, and compensating controls in full report.

Recommended ActionAI

Within 24 hours, identify all FileBrowser instances in your environment and verify their current version; if running versions before 2.63.19, apply the vendor-released patch immediately or disable public self-registration as an interim measure. …

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