CVE-2026-73405 Authorization Bypass in SSE Pub/Sub Allows Unconfirmed Accounts to Access Stream Events in vulnerability-lookup

Medium 5.3 Published Updated

Attackers with unconfirmed accounts can access restricted SSE streams, exposing unmoderated data due to missing active status checks.

Exploited in the wild
Not known
Login needed
Any signed-in user
Attackable
Over the internet
Victim action needed
Not needed
Fix
None listed

What is CVE-2026-73405?

CVE-2026-73405 is a medium-severity missing authorization vulnerability in vulnerability-lookup, published on 12 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

An authorization bypass vulnerability in Vulnerability-Lookup allowed inactive or unconfirmed accounts to subscribe to Server-Sent Events (SSE) streams through the /pubsub/subscribe/<topic> endpoint.

The token_required decorator used by the Pub/Sub interface authenticated requests solely by matching the X-API-KEY header against an existing user API key. Unlike the REST API authentication mechanism, it did not verify the account's is_active and is_confirmed state.

Because the self-registration process issues an API key before account confirmation is completed, an attacker could create an account and immediately use the resulting API key to access Pub/Sub topics that should only be available to active, confirmed users. This could expose stream events that would otherwise be inaccessible through the REST API, including newly submitted or not-yet-moderated data such as comments.

The vulnerability results from inconsistent authorization enforcement between the REST API and the SSE streaming interface.

The patch corrects the issue by requiring accounts to be both active and confirmed before permitting access to Pub/Sub streams, bringing the SSE authorization boundary in line with the REST API.

Weakness: CWE-862

Which versions are affected by CVE-2026-73405?

How do I fix CVE-2026-73405?

No fix has been published for CVE-2026-73405 yet. Limit exposure of the affected software until one is available.

Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.

Is CVE-2026-73405 being exploited?

There is no known exploitation of CVE-2026-73405 in the wild and no public exploit code.

Sources

Also known as GHSA-8gv5-4q99-4cxm.

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