Vulnerability · Published Apr 2, 2026 · Assigned by NCSC.ch
CVE-2026-29137Long Subject Untagging
Medium 5.3
In plain English
A medium-severity improper input validation in Secure Email Gateway from SEPPmail. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 9% of all known vulnerabilities).
Severity (CVSS 4.0)5.3Medium
Exploit odds (30 days)0.2%top 91.0% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
SEPPmail Secure Email Gateway before version 15.0.3 allows an attacker to hide security tags from users by crafting a long subject.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| SEPPmail | Secure Email Gateway | 0 – before 15.0.3 |
Weakness: CWE-20 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N