CVE-2026-29137 PUBLISHED

Long Subject Untagging

Assigner: NCSC.ch
Reserved: 04.03.2026 Published: 02.04.2026 Updated: 02.04.2026

SEPPmail Secure Email Gateway before version 15.0.3 allows an attacker to hide security tags from users by crafting a long subject.

CVSS 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
CVSS Score: 5.3

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	None	Confidentiality	None
Attack Complexity	Low	Integrity	Low	Integrity	Low
Attack Requirements	None	Availability	None	Availability	None
Privileges Required	None
User Interaction	Passive

CVSS 4.0

Vendor	SEPPmail
Product	Secure Email Gateway
Versions	Default: unaffected affected from 0 to 15.0.3 (excl.)