Raw vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:H/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:XSummary
CVE-2026-35585 is a high-severity OS Command Injection (CWE-78) vulnerability in Filebrowser Filebrowser. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Command and Scripting Interpreter (T1059); ranked in the top 22% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
File Browser is a web-based file management interface that supports operations such as uploading, renaming, and deleting files inside a configured directory. CVE-2026-35585 affects the hook system in versions 2.0.0 through 2.33.8, where administrator-defined shell commands are executed on file events. Variable substitution for placeholders such as $FILE and $USERNAME is performed with Go’s os.Expand function without any sanitization, allowing shell metacharacters to be interpreted by the underlying operating system and resulting in OS command injection (CWE-78, CWE-88).
An attacker who already possesses file-write permission within the managed directory can create or rename a file whose name contains shell metacharacters. When a subsequent file event triggers the configured hook, the server executes the attacker-supplied command, yielding remote code execution with the privileges of the File Browser process. The CVSS 7.5 score reflects network attack vector, low attack complexity once the precondition is met, and high impact on confidentiality, integrity, and availability.
Public advisories hosted on the project’s GitHub repository state that the hook feature has been disabled by default in version 2.33.8 for both new and existing installations. Administrators are advised to upgrade to at least this release and to review any previously defined hooks before re-enabling the functionality.
The associated EPSS score rose from a low baseline to a peak of 0.0109, indicating that exploitation interest increased after disclosure.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-19775
Vulnerability Data
File Browser is a file managing interface for uploading, deleting, previewing, renaming, and editing files within a specified directory. From 2.0.0 until 2.33.8, the hook system in File Browser — which executes administrator-defined shell commands on file events such as…
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upload, rename, and delete — is vulnerable to OS command injection. Variable substitution for values like $FILE and $USERNAME is performed via os.Expand without sanitization. An attacker with file write permission can craft a malicious filename containing shell metacharacters, causing the server to execute arbitrary OS commands when the hook fires. This results in Remote Code Execution (RCE). This feature has been disabled by default for all installations from v2.33.8 onwards, including for existent installations.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V1.2.5V1.2.8V15.2.5
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation can discover missing or incorrect command sanitization during development.
Input validation directly neutralizes or rejects special characters that would otherwise alter OS command structure.
Least privilege reduces the permissions available to any process that could be subverted by injected commands.
Least functionality restricts available OS commands and interpreters, limiting the blast radius of injection.
Secure engineering principles require proper neutralization of untrusted input before command construction.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
PR.PS-06's SDLC practices directly require secure coding and input handling that blocks command-injection defects, yet the single broad outcome leaves many specific neutralization vectors and verification gaps unaddressed.
Routine patching/maintenance can remediate known command-injection CVEs in dependencies (partial forward) but does nothing to stop developers from introducing improper neutralization in custom code (none reverse).
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing and code review target insecure use of operating-system command interfaces, catching command-injection flaws introduced during development.
Secure development lifecycle mandates input validation and command construction practices that directly prevent argument injection.
Application security requirements include explicit rules for safe command-line argument handling and escaping.
Secure architecture principles discourage unsafe command invocation patterns and favor safer APIs.
Secure coding standards explicitly require proper neutralization of command arguments, directly eliminating CWE-88.
Change management can catch unsafe command patterns during reviews but is not a direct mitigation.