CVE-2026-55878 Symfony: Path Traversal in symfony/ux-toolkit Allows Arbitrary File Write and Read via Crafted Recipe Manifest
Attackers can write arbitrary files or read local files via crafted recipe manifests in Symfony UX toolkit, potentially leading to code execution.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-55878?
CVE-2026-55878 is a high-severity path traversal vulnerability in symfony ux, published on 8 Jul 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official 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.
Weakness: CWE-22
Which versions are affected by CVE-2026-55878?
4 open source packages ship an affected version, including symfony/ux-toolkit.
| Package | Affected | Fixed in |
|---|---|---|
symfony/ux-toolkit Packagist | From 2.32.0 | 2.36.1 |
symfony/ux-toolkit Packagist | From 2.32.0 | 2.36.1 |
symfony/ux-toolkit Packagist | From 3.0.0 | 3.2.0 |
symfony/ux-toolkit Packagist | From 3.0.0 | 3.2.0 |
How do I fix CVE-2026-55878?
Upgrade symfony/ux-toolkit to a fixed version for your release line: 2.36.1 or 3.2.0.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-55878 being exploited?
There is no known exploitation of CVE-2026-55878 in the wild and no public exploit code.
Sources
Also known as GHSA-p9xj-fpr2-jf2q.