Auth bypass in Acymailing Newsletter Team Anti Spam And List Cleaner – Acychecker

CVE-2026-66689

Unauthenticated Broken Access Control in Anti Spam and list cleaner &#8211; AcyChecker <= 2.0.0 versions.

Vulnerability class: Broken Access Control

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L.

EPSS exploit prediction

EPSS: 0.003 (15.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 16th percentile — 15.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-66689: held from 0.002 to 0.003.

EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-66689?
CVE-2026-66689 is a medium-severity vulnerability in Acymailing Newsletter Team Anti Spam And List Cleaner &#8211; Acychecker, classified under Missing Authorization. CVSS score: 6.3/10. Published 2026-08-13.
How severe is CVE-2026-66689?
Medium severity. CVSS v3 base score is 6.3 out of 10.