6.1

CVE-2026-49210: symfony ux Cross-site Scripting

CVSS: 6.1v3.1MediumAnalyzed
Published 17-07-2026Last modified 17-07-2026
Open JSON

Vulnerability summary

CVE-2026-49210 is a medium (CVSS 6.1) Cross-site Scripting vulnerability in symfony ux. EPSS estimates a 0.34% chance of exploitation in the next 30 days, higher than 25.7% of scored vulnerabilities.

Overall risk
24/100
0100
Low · default modelHow is this calculated?
CVSS score
6.1/10
010
Medium · v3.1 (NVD)
EPSS score
0.34%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 17-07-2026
    PublishedVulnerability first disclosed.
  2. 17-07-2026
    Last modifiedVulnerability information updated.

Description

Symfony UX is a JavaScript ecosystem for Symfony. From 2.8.0 until 2.36.0 and 3.1.0, Symfony\UX\LiveComponent\Util\ChildComponentPartialRenderer::createHtml() interpolates the client-controlled children[id].tag value from LiveComponentSubscriber and InterceptChildComponentRenderSubscriber directly into HTML as a tag name without escaping or validation, allowing arbitrary HTML, including <script> tags, on any Live Component re-render that contains at least one child component. This issue is fixed in versions 2.36.0 and 3.1.0.

CVSS metrics

3 scores · 2 sources · 2 versions

EPSS trend

Probability

0.34%

Chance of exploitation in the next 30 days

Percentile

26%

Versus all other CVEs

30-day change

0.00 pp

From 0.34% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.34%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Symfony1 product
  • ux≥ 3.0.0, < 3.1.0 | ≥ 2.8.0, < 2.36.0 | 3.0.0

1 vendor · 1 product

References

4 links