CVE-2026-35389 HIGH

CVE-2026-35389: Bulwark Webmail S/MIME signature verification accepted self-signed certificates

Vendor Bulwarkmail
Product webmail
Weakness CWE-295
Published April 6, 2026
Last update April 7, 2026
View on NVD All CVEs

CVSS base score

8.7/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality —
Integrity —

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

What the vulnerability does

01Description

Bulwark Webmail is a self-hosted webmail client for Stalwart Mail Server. Prior to 1.4.11, S/MIME signature verification did not validate the certificate trust chain (checkChain: false). Any email signed with a self-signed or untrusted certificate was displayed as having a valid signature. This vulnerability is fixed in 1.4.11.

Key dates

02Disclosure timeline

April 6, 2026 CVE published
April 7, 2026 Record updated