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Fencer Vulns
medium 5.3

CVE-2026-73405 json

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

published 2026-08-12 2 mo ago modified 2026-08-26 2 mo ago also EUVD-2026-57223

cvss
5.3
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 42%
public exploits
0
none known

Summary

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.

Patch / fix

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 mo ago

Exploit prediction

0.50% chance of exploitation in the next 30 days, higher than 42% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 5.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
CNA 4.0 5.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

  • vulnerability-lookup vulnerability-lookup

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.