CVE-2026-49212
HighCVSS 7.5Exploitation Probability (EPSS)
Low risk8th percentile - higher than 8% of all known CVEs
Summary
A vulnerability in Symfony UX allows an attacker to swap a signed data blob between components or slots, enabling the setting of read-only properties on a target component. Affected versions are from 2.8.0 to 2.36.0 and 3.1.0.
Risk Assessment
An attacker can exploit this to manipulate Live Component state, potentially leading to unauthorized data changes or privilege escalation within the application.
Recommendation
Upgrade Symfony UX to version 2.36.0 or 3.1.0 immediately, which include a fix preventing replay attacks.
Other vulnerabilities in Symfony UX
See all- CVE-2026-49215Medium
A vulnerability in Symfony UX allows CSRF attacks on LiveComponent components. The protection mechanism relies on the Accept header, which can be set by an attacker in a cross-origin request without preflight, enabling unauthorized actions on a victim's session.
- CVE-2026-49211High
A vulnerability in Symfony UX allows unauthenticated users to turn the public autocomplete endpoint into a broad matcher or blind boolean oracle. The issue is due to missing escaping of SQL LIKE wildcards (% , _ , \) in the client-supplied query.
- CVE-2026-49210Medium
A vulnerability in Symfony UX allows arbitrary HTML injection, including <script> tags, during Live Component re-rendering. The client-controlled children[id].tag value is interpolated directly into HTML without escaping or validation.
- CVE-2026-49209Medium
A vulnerability in Symfony UX allows an authenticated client to send a single _batch request with thousands of actions, exhausting server resources (CPU, memory, database connections) due to unbounded iteration over the actions array.
- CVE-2026-49208Medium
A vulnerability in Symfony UX allows an attacker to manipulate dates by sending relative strings (e.g., now, tomorrow, +10 years) to a LiveProp of type DateTimeInterface without a configured format. This bypasses time-based business logic checks.
- CVE-2026-55878High
A vulnerability in Symfony UX allows writing files to arbitrary locations or reading local files outside the recipe directory via a crafted recipe kit. The issue affects the ux:install console command which uses Path::isRelative() accepting paths like ../../../etc.
- CVE-2026-55877Medium
A vulnerability in Symfony UX allows XSS via the ux_icon() Twig function, which marks output as safe (is_safe=['html']) and embeds SVG source verbatim. Unsanitized local SVG files or Iconify JSON responses can contain malicious scripts, event handlers, or dangerous URL schemes.
Original NVD description (English source)
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.