CVE-2026-42565

@workos/authkit-session: Open Redirect via state-derived redirect target

MEDIUM
4.3
CVSS Score
Published: May 11, 2026 at 07:01 PM UTC
Updated: October 26, 2026 at 06:10 PM UTC
1 product affected across 1 vendorAuthKit Session

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Severity
MEDIUM4.3
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

@workos/authkit-session is a toolkit for building WorkOS AuthKit framework integrations. Prior to 0.5.1, an open redirect vulnerability exists in AuthService.handleCallback due to insufficient validation of the returnPathname value derived from the OAuth state parameter. The state parameter is round-tripped through the identity provider (IdP) and can be influenced by an attacker. The handleCallback function decodes and returns returnPathname without enforcing restrictions on origin or scheme. As a result, attacker-controlled values may be returned to the application. If this value is used directly in a redirect, it may cause the user to be redirected to an external, attacker-controlled site. This vulnerability is fixed in 0.5.1.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 0.5.1
Affected range stops below 0.5.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

4.3MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
NONE
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-601

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