Improper input validation in Symfony Ux

CVE-2026-49208

Symfony UX is a JavaScript ecosystem for Symfony. From 2.8.0 until 2.36.0 and 3.1.0, when a #[LiveProp] is typed as DateTimeInterface and no explicit format is configured, Symfony\UX\LiveComponent\LiveComponentHydrator::hydrateObjectValue() falls back to new $className($value), allowing client-supplied relative strings such as now, tomorrow, or +10 years to move a writable, format-less date prop past time-based business logic checks. This issue is fixed in versions 2.36.0 and 3.1.0.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.004 (34.3th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 34th percentile — 34.3% 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-2026-49208: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

  • Symfony Ux — versions >= 2.8.0, < 2.36.0, >= 3.0.0, < 3.1.0, 3.0.0

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-49208?
CVE-2026-49208 is a medium-severity vulnerability in Symfony Ux, classified under Improper Input Validation. CVSS score: 5.3/10. Published 2026-07-17.
How severe is CVE-2026-49208?
Medium severity. CVSS v3 base score is 5.3 out of 10.