CVE-2026-29135 Webmail Password Tag Sanitization Bypass

Medium 5.3 Published 2 Apr 2026 Updated 2 Apr 2026

Attackers can bypass subject sanitization in SEPPmail Secure Email Gateway by crafting a malicious password tag, undermining email security controls.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: A user has to click or open something
Fix: None listed

What is CVE-2026-29135?

CVE-2026-29135 is a medium-severity vulnerability in SEPPmail Secure Email Gateway, published on 2 Apr 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

SEPPmail Secure Email Gateway before version 15.0.3 allows an attacker to craft a password-tag that bypasses subject sanitization.

Weakness: CWE-20

Which versions are affected by CVE-2026-29135?

It affects 1 product.

Products include Seppmail Secure Email Gateway.

How do I fix CVE-2026-29135?

No fix has been published for CVE-2026-29135 yet. Limit exposure of the affected software until one is available.

Is CVE-2026-29135 being exploited?

There is no known exploitation of CVE-2026-29135 in the wild and no public exploit code.

Sources

Also known as GHSA-96h6-qp9f-fc25.