SB2026061979 - Deserialization of Untrusted Data in React Router

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Main Vulnerability Database SB2026061979

SB2026061979 - Deserialization of Untrusted Data in React Router

Published: June 19, 2026

Security Bulletin ID SB2026061979
CSH Severity
High
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

High 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Deserialization of Untrusted Data (CVE-ID: CVE-2026-42211)

CWE-ID: CWE-502 - Deserialization of Untrusted Data

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber


The vulnerability allows a remote attacker to execute arbitrary code.

The vulnerability exists due to deserialization of untrusted data in React Router framework mode when handling external requests in an application that also contains an existing prototype pollution vulnerability. A remote attacker can send crafted external requests to execute arbitrary code.

Exploitation requires chaining with a pre-existing prototype pollution vulnerability in the application code and affects framework mode only.


Remediation

Install update from vendor's website.

References