CVE intelligence and bounded remediation

CVE-2026-54414 — FileRise security vulnerability

Critical CVSS 9.8

FileRise before 3.16.0 is vulnerable to path traversal in the shared-folder upload endpoint (/api/folder/uploadToSharedFolder.php), leading to arbitrary file write and administrator account takeover. The upload filename is validated by FolderController with basename() and REGEX_FILE_NAME, which permit URL-encoded sequences (the regex blocks / and \ but not %). The raw filename is then passed to UploadModel::handleUpload, where it is reconstructed as trim(urldecode(basename($fileName))), re-introducing path separators after validation (e.g. ..%2fusers%2fusers.txt becomes ../users/users.txt). UploadNamePolicy::isAllowedForWrite() applies basename() internally and therefore only evaluates the final component (users.txt), allowing the traversal sequence to pass the extension policy. The destination path is then used directly in move_uploaded_file() with no realpath containment check, allowing a write outside the intended upload directory. An attacker who possesses a valid, non-expired, upload-enabled shared-folder link/token (which are designed to be shared publicly) can overwrite users/users.txt to create an administrator account, resulting in unauthenticated admin takeover and, depe…

Severity
Critical
CVSS
9.8 (3.1)
Published
2026-06-19
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-22, CWE-434

Affected products

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Matched remediation archetype

Path traversal, unsafe upload, and file handling

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Check exposure

  • Trace untrusted filenames, archive entries, URLs, and path segments into read, write, include, extraction, and upload operations.
  • Identify filesystem roots, mount permissions, symbolic-link behavior, archive handling, and whether uploaded content is web-accessible or executable.
  • Review canonicalization and containment checks across supported operating systems and storage backends.

Remediate safely

  • Generate server-side storage identifiers and resolve paths beneath a fixed root using filesystem-aware containment checks.
  • Reject absolute, parent-relative, alternate-separator, device, link, and archive entries that escape the intended root.
  • Store uploads outside executable or served paths, validate type and size, and use private atomic temporary files.

Authoritative sources

Complete CVE record and remediation plan

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