Auth bypass in Newsletters

CVE-2026-16269

The Newsletters WordPress plugin before 4.16 does not strictly compare its API authentication key, allowing unauthenticated attackers to bypass the API authentication via type juggling and perform privileged actions such as modifying subscriber records and sending emails, when the optional API has been enabled.

Vulnerability class: Broken Authentication

EPSS: 0.002 (13.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L.

Affected products

  • Unknown Newsletters — versions 0

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-16269?
CVE-2026-16269 is a medium-severity vulnerability in Newsletters, classified under Improper Authentication. CVSS score: 4.8/10. Published 2026-08-08.
How severe is CVE-2026-16269?
Medium severity. CVSS v3 base score is 4.8 out of 10.