CVE intelligence and bounded remediation

CVE-2026-4809 — plank/laravel-mediable security vulnerability

Critical CVSS 9.8

plank/laravel-mediable through version 6.4.0 can allow upload of a dangerous file type when an application using the package accepts or prefers a client-supplied MIME type during file upload handling. In that configuration, a remote attacker can submit a file containing executable PHP code while declaring a benign image MIME type, resulting in arbitrary file upload. If the uploaded file is stored in a web-accessible and executable location, this may lead to remote code execution. At the time of publication, no patch was available and the vendor had not responded to coordinated disclosure attempts.

Severity
Critical
CVSS
9.8 (3.1)
Published
2026-03-26
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
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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