CVE-2026-29140 | BDVDB-2026-324370 Detail

SEPPmailSecure Email Gateway

Description#

SEPPmail Secure Email Gateway before version 15.0.3 allows an attacker to cause attacker-controlled certificates to be used for future encryption to a victim by adding the certificates to S/MIME signatures.

Impact#

CAPEC-216 Communication Channel Manipulation

Weaknesses#

CWE-295 Improper Certificate Validation

References#

https://downloads.seppmail.com/extrelnotes/150/ERN15.0.html#seppmail-vulnerability-disclosure-1503

Exploit#

No public exploit known

History#

Version 12026-04-02Record published in the CVE List.

Published

Published: 2026-04-02
Last modified: 2026-04-02

Vendor information

Vendor: SEPPmail
Product: Secure Email Gateway

All SEPPmail vulnerabilities

Score

7.7 High

EPSS

less than 1%, Very Low

Estimated chance of exploitation in the next 30 days. EPSS percentile: 2.0.

KEV

Not listed in the CISA Known Exploited Vulnerabilities catalog.

Impact

Not classified

Action

No specific action is recorded in the source data. Check the references for vendor guidance.

Affected Systems

Vulnerable
< 15.0.3
Fixed
15.0.3

Scoring System

CVSS v4.0

7.7 High

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

Metric breakdown
Attack Vector	Network
Attack Complexity	Low
Attack Requirements	None
Privileges Required	None
User Interaction	None
Vulnerable System Confidentiality	None
Vulnerable System Integrity	Low
Vulnerable System Availability	None
Subsequent System Confidentiality	High
Subsequent System Integrity	None
Subsequent System Availability	None

CVSS v3.1

Not available

CVSS v3.0

Not available

CVSS v2

Not available

Source: CVE List v5 (record); CISA KEV (kev, action); FIRST EPSS (epss).