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

Is it exploited?

Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of 29 Oct 2026. If CISA adds it, this page shows it as known exploited.

How likely is exploitation in the next 30 days?

0.5%

EPSS score, percentile 42.6 of all scored records. A probability estimated by FIRST, not a report of exploitation.

How severe?

5.3 Medium

CVSS v4.0 base score, given by the CNA

What should I do?

CISA has set no required action, because the vulnerability is not in KEV.

Advisories and patches (1)

Which versions are affected?

Affected

• 5.5.1 and earlier

Versions by product

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; FIRST EPSS, as of 29 Oct 2026; CVE List, as of 29 Oct 2026. About the data.

What to do

Advisories and patches

• github.com (Patch)

This summary is based on the CVE record as of 29 Oct 2026. Check the vendor's advisory before you act: affected versions and fixes can change.

Affected products and versions

As listed in the CVE record.

Versions not listed are: unaffected.

Source: CVE List, as of 29 Oct 2026. About the data.

About this vulnerability

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 mechan…

Summary: CVE record, as of 29 Oct 2026.

• CISA has not added CVE-2026-73405 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
• The CVE record was published on 12 Aug 2026.
• The CVE record carries a CVSS v4.0 base score of 5.3 (Medium), given by its CNA.
• FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.5% (percentile 42.6), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
• CISA's SSVC assessment in the CVE record: exploitation none, automatable no, technical impact partial.
• The credits in the CVE record name OpenAI as finder.

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; CVE List, as of 29 Oct 2026; FIRST EPSS, as of 29 Oct 2026. About the data.

Description

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

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.

Source: CVE List, as of 29 Oct 2026. About the data.

Timeline