What is CVE-2026-27064?

CVE-2026-27064 is a critical-severity vulnerability in Everpress Mailster, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 9.1/10. Published 2026-07-23.

How severe is CVE-2026-27064?

Critical severity. CVSS v3 base score is 9.1 out of 10.

Arbitrary file upload in Everpress Mailster

CVE-2026-27064

Editor Arbitrary File Upload in Mailster <= 4.1.17 versions.

Vulnerability class: Unrestricted File Upload

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H.

Affected products

Everpress Mailster — versions n/a

Weakness classification (CWE)

CWE-434 — Unrestricted Upload of File with Dangerous Type

References

audit@patchstack.com (vdb-entry)

Frequently asked questions

What is CVE-2026-27064?: CVE-2026-27064 is a critical-severity vulnerability in Everpress Mailster, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 9.1/10. Published 2026-07-23.
How severe is CVE-2026-27064?: Critical severity. CVSS v3 base score is 9.1 out of 10.