Path Traversal in Symfony Ux

CVE-2026-55878

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.

Vulnerability class: Path Traversal (Directory Traversal)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.002 (8.1th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 8th percentile — 8.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-55878: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

  • Symfony Ux — versions >= 2.32.0, < 2.36.1, >= 3.0.0, < 3.2.0

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-55878?
CVE-2026-55878 is a high-severity vulnerability in Symfony Ux, classified under Path Traversal. CVSS score: 7.8/10. Published 2026-07-08.
How severe is CVE-2026-55878?
High severity. CVSS v3 base score is 7.8 out of 10.