CVE-2026-49212CWE-345

Symfony UX: LiveComponentHydrator HMAC checksum lacks component and slot binding

Medium · published July 17, 2026

CVSS v4.0
6.9
EPSS
0%
Percentile
14.5
In the wild
Unconfirmed
What it is

Symfony UX is a JavaScript ecosystem for Symfony. From 2.8.0 until 2.36.0 and 3.1.0, the HMAC computed by Symfony\UX\LiveComponent\LiveComponentHydrator covered only sorted prop key/value pairs and did not include the component name, the slot identifier (props vs propsFromParent), or request context, allowing a signed blob minted for one component or slot to be replayed in another and set a read-only prop on a target component. This issue is fixed in versions 2.36.0 and 3.1.0.

The record
Technical detail
CVSS v4.0
6.9 · MEDIUM
Vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
EPSS
0.00242 · 14.5th percentile
Weakness
CWE-345 · Insufficient Verification of Data Authenticity
Published
2026-07-17T16:03Z
EPSS history
Timeline
  • 17 JUL 16:03Z
    Symfony UX: LiveComponentHydrator HMAC checksum lacks component and slot binding
    cvelistv5