CVE-2026-42565 @workos/authkit-session: Open Redirect via state-derived redirect target
Attackers can redirect users to malicious sites via unvalidated OAuth state parameters in the WorkOS AuthKit session library.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-42565?
CVE-2026-42565 is a medium-severity vulnerability in workos authkit-session, published on 11 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official 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.
Weakness: CWE-601
Which versions are affected by CVE-2026-42565?
2 open source packages ship an affected version, including @workos/authkit-session.
| Package | Affected | Fixed in |
|---|---|---|
@workos/authkit-session npm | All versions | 0.5.1 |
@workos/authkit-session npm | All versions | 0.5.1 |
How do I fix CVE-2026-42565?
Upgrade @workos/authkit-session to 0.5.1 or later.
Is CVE-2026-42565 being exploited?
There is no known exploitation of CVE-2026-42565 in the wild and no public exploit code.
Sources
Also known as GHSA-vvvv-983w-r7pv.