PT-2026-30727 · Unknown · Stalwart Mail Server+1

Richardweinberger · CVE-2026-35389 · Published 2026-04-06 · Updated 2026-04-06

Positive Technologies (AI Summary)

CVSS v4.0

8.7

High

Base vector

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

Name of the Vulnerable Software and Affected Versions Bulwark Webmail versions prior to 1.4.11

Description Bulwark Webmail, a self-hosted webmail client for Stalwart Mail Server, had an issue in S/MIME signature verification. Before version 1.4.11, the software did not validate the certificate trust chain during signature verification. This meant that emails signed with self-signed or untrusted certificates were incorrectly displayed as having valid signatures.

Recommendations Update to version 1.4.11 or later.

Exploit

Fix

Improper Certificate Validation

Weakness Enumeration

CWE-295

Related Identifiers

CVE-2026-35389

GHSA-V6W6-338P-P256

Affected Products

Bulwark Webmail

Stalwart Mail Server

References · 6

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/35xxx/CVE-2026-35389.json · Exploit
• https://github.com/bulwarkmail/webmail/security/advisories/GHSA-v6w6-338p-p256 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-35389 · Security Note
• https://osv.dev/vulnerability/CVE-2026-35389 · Vendor Advisory
• https://twitter.com/infoflowcloud/status/2041261120481091817 · Twitter Post
• https://twitter.com/CVEnew/status/2041260650069217392 · Twitter Post