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RSCErrorHandler Missing Protocol Validation (XSS)

Moderate
brophdawg11 published GHSA-h8fp-f39c-q6mh Jul 22, 2026

Package

npm react-router (npm)

Affected versions

>=7.11.0,<7.18.0

Patched versions

>=7.18.0

Description

This is a follow up to GHSA-8646-j5j9-6r62. We were alerted of a code path in the (unstable) RSC error handling path in which redirects from untrusted sources could still result in an XSS vector via attacker-supplied redirect targets

Note

This only affects your application if you are using the unstable RSC APIs

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
Required
Scope
Changed
Confidentiality
High
Integrity
Low
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:L/A:N

CVE ID

CVE-2026-53667

Weaknesses

No CWEs

Credits