SB2026031906 - Remote code execution in Remix React and React Router
Published: March 19, 2026
Security Bulletin ID
SB2026031906
Severity
High
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Data manipulation
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 security vulnerability.
1) Code Injection (CVE-ID: CVE-2026-21884)
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to improper input validation within API in Framework Mode when using the getKey/storageKey props during server-side rendering. A remote attacker can pass specially crafted request and execute arbitrary JavaScript code during SSR if untrusted content is used to generate the keys.
Successful exploitation of this vulnerability requires that server-side rendering in Framework Mode is enabled.
Remediation
Install update from vendor's website.