CVE-2026-1435 Incorrect management of session invalidation vulnerability in Graylog Web Interface

Critical 9.3 Published 18 Feb 2026 Updated 18 Feb 2026

Attackers can reuse old session tokens to gain unauthorized access to Graylog accounts due to improper session invalidation.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-1435?

CVE-2026-1435 is a critical authentication bypass vulnerability in Graylog Web Interface, published on 18 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Not properly invalidated session vulnerability in Graylog Web Interface, version 2.2.3, due to incorrect management of session invalidation after new logins. The application generates a new 'sessionId' each time a user authenticates, but does not invalidate previously issued session identifiers, which remain valid even after multiple consecutive logins by the same user. As a result, a stolen or leaked 'sessionId' can continue to be used to authenticate valid requests. Exploiting this vulnerability would allow an attacker with access to the web service/API network (port 9000 or HTTP/S endpoint of the server) to reuse an old session token to gain unauthorized access to the application, interact with the API/web, and compromise the integrity of the affected account.

Weakness: CWE-613

Which versions are affected by CVE-2026-1435?

It affects 1 product.

Products include Graylog Graylog.

How do I fix CVE-2026-1435?

No fix has been published for CVE-2026-1435 yet. Limit exposure of the affected software until one is available.

Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.

Is CVE-2026-1435 being exploited?

There is no known exploitation of CVE-2026-1435 in the wild and no public exploit code.

Sources

Also known as GHSA-3crm-x896-j73p.