What is CVE-2026-29133?

CVE-2026-29133 is a critical-severity vulnerability in Seppmail Secure Email Gateway, classified under Improper Input Validation. CVSS score: 9.1/10. Published 2026-04-02.

How severe is CVE-2026-29133?

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

Improper input validation in Seppmail Secure Email Gateway

CVE-2026-29133

SEPPmail Secure Email Gateway before version 15.0.3 allows an attacker to upload PGP keys with UIDs that do not match their email address.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

EPSS: 0.002 (14.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

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

Affected products

Seppmail Secure Email Gateway — versions 0
Seppmail Secure_email_gateway

Weakness classification (CWE)

CWE-20 — Improper Input Validation

References

vulnerability@ncsc.ch (release-notes, Release Notes)

Frequently asked questions

What is CVE-2026-29133?: CVE-2026-29133 is a critical-severity vulnerability in Seppmail Secure Email Gateway, classified under Improper Input Validation. CVSS score: 9.1/10. Published 2026-04-02.
How severe is CVE-2026-29133?: Critical severity. CVSS v3 base score is 9.1 out of 10.