CVE-2026-35408

Directus's Single Sign-On (SSO) login pages lacked a Cross-Origin-Opener-Policy (COOP) HTTP response header. Without this header, a malicious cross-origin window that opens the Directus login page retains the ability to access and manipulate the window object of that page. An attacker can exploit this to intercept and redirect the OAuth authorization flow to an attacker-controlled OAuth client, causing the victim to unknowingly grant access to their authentication provider account (e.g. Google, Discord).

Workarounds

Users who are unable to upgrade immediately can mitigate this vulnerability by configuring their reverse proxy or web server to add the following HTTP response header to all Directus responses: Cross-Origin-Opener-Policy: same-origin

A successful attack allows the attacker to obtain an OAuth access token for the victim's third-party identity provider account. Depending on the scopes authorized, this can lead to:

• Unauthorized access to the victim's linked identity provider account
• Account takeover of the Directus instance if the attacker can authenticate using the stolen credentials or provider session

CVE-2026-35408 has a CVSS score of 8.7 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (11.17.0); upgrading removes the vulnerable code path.

Kodem intelligence

This issue has been addressed by adding the Cross-Origin-Opener-Policy: same-origin HTTP response header to SSO-related endpoints. This header instructs the browser to place the page in its own browsing context group, severing any reference the opener window may hold.

1. What is CVE-2026-35408? CVE-2026-35408 is a high-severity security vulnerability in directus (npm), affecting versions < 11.17.0. It is fixed in 11.17.0.
2. How severe is CVE-2026-35408? CVE-2026-35408 has a CVSS score of 8.7 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of directus are affected by CVE-2026-35408? directus (npm) versions < 11.17.0 is affected.
4. Is there a fix for CVE-2026-35408? Yes. CVE-2026-35408 is fixed in 11.17.0. Upgrade to this version or later.
5. Is CVE-2026-35408 exploitable, and should I be worried? Whether CVE-2026-35408 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-35408 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-35408? Upgrade directus to 11.17.0 or later.