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)

Published 2026-04-02 · last modified 2026-06-17.

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.

EPSS exploit prediction

EPSS: 0.004 (31.2th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 31st percentile — 31.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.004 · change: +0.002

Affected products

Seppmail Secure Email Gateway — versions 0
Seppmail Secure Email Gateway

Weakness classification (CWE)

CWE-20 — Improper Input Validation

References

downloads.seppmail.com/extrelnotes/150/ERN15.0.html (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.