CVE-2026-55878: symfony ux Path Traversal

Vulnerability summary

CVE-2026-55878 is a high (CVSS 7.8) Path Traversal vulnerability in symfony ux. EPSS estimates a 0.19% chance of exploitation in the next 30 days, higher than 8.3% of scored vulnerabilities.

Timeline

1. 08-07-2026
   PublishedVulnerability first disclosed.
2. 09-07-2026
   Last modifiedVulnerability information updated.

Description

Symfony UX is a JavaScript ecosystem for Symfony. From 2.32.0 before 2.36.1 and from 3.0.0 before 3.2.0, the ux:install console command installs files from a recipe kit by copying paths listed in a copy-files map, and because Path::isRelative() accepts paths like ../../../etc, a crafted or compromised kit can write attacker-controlled content to arbitrary locations or read local files outside the recipe directory. This issue is fixed in versions 2.36.1 and 3.2.0.

• CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.