XSS in Symfony Ux

CVE-2025-47946

Symfony UX is an initiative and set of libraries to integrate JavaScript tools into applications. Prior to version 2.25.1, rendering `{{ attributes }}` or using any method that returns a `ComponentAttributes` instance (e.g. `only()`, `defaults()`, `without()`) ouputs attribute values directly without escaping. If these values are unsafe (e.g. contain user input), this can lead to HTML attribute injection and XSS vulnerabilities. The issue is fixed in version `2.25.1` of `symfony/ux-twig-component` Those who use `symfony/ux-live-component` must also update it to `2.25.1` to benefit from the fix, as it reuses the `ComponentAttributes` class internally. As a workaround, avoid rendering `{{ attributes }}` or derived objects directly if it may contain untrusted values. Instead, use `{{ attributes.render('name') }}` for safe output of individual attributes.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.003 (15.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 16th percentile — 15.8% 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-2025-47946: held from 0.002 to 0.003.

EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-47946?
CVE-2025-47946 is a medium-severity vulnerability in Symfony Ux, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2025-05-19.
How severe is CVE-2025-47946?
Medium severity. CVSS v3 base score is 6.1 out of 10.
Is CVE-2025-47946 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.