CVE-2026-2747
Published: 04 March 2026
Summary
CVE-2026-2747 is a high-severity Exposure of Sensitive Information to an Unauthorized Actor (CWE-200) vulnerability in Seppmail Seppmail. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 14.3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
Threat & Defense at a Glance
Threat & Defense Details
Likely Mitigating ControlsAI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Automated marking applies security attributes to system outputs, making it harder for attackers to exploit unmarked sensitive information leading to unauthorized exposure.
Proper attribute retention and permitted-value enforcement limits unauthorized actors from accessing sensitive information lacking correct labels.
Prevents unauthorized exposure of sensitive information by prohibiting untrusted external systems from processing or storing it.
By enforcing authorization matching prior to sharing, the control reduces the risk of exposing sensitive information to unauthorized actors.
Review and removal of nonpublic information from publicly accessible systems directly prevents exposure of sensitive data to unauthorized actors.
Data mining protection mechanisms detect and block unauthorized bulk extraction of sensitive data, directly mitigating exposure to unauthorized actors.
Literacy training teaches users to recognize and avoid actions that result in unauthorized exposure of sensitive information.
Retaining and monitoring training records confirms personnel have completed privacy and security awareness training on handling sensitive data, reducing the chance of unauthorized exposure due to lack of knowledge.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
The CVE describes remote exploitation of a public-facing email gateway via crafted emails that trigger improper PGP decryption and sensitive data exposure (CWE-200), directly enabling T1190.
NVD Description
SEPPmail Secure Email Gateway before version 15.0.1 decrypts inline PGP messages without isolating them from surrounding unencrypted content, allowing exposure of sensitive information to an unauthorized actor.
Deeper analysisAI
CVE-2026-2747 affects SEPPmail Secure Email Gateway versions prior to 15.0.1. The vulnerability arises because the software decrypts inline PGP messages without isolating the decrypted content from surrounding unencrypted email content. This flaw, classified under CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor), carries a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N), indicating high confidentiality impact with network accessibility, low attack complexity, and no requirements for privileges or user interaction.
An unauthorized remote attacker can exploit this vulnerability by sending a specially crafted email containing an inline PGP message to a targeted SEPPmail Secure Email Gateway. Upon processing, the gateway decrypts the PGP-encrypted content without proper isolation, potentially exposing sensitive information within the decrypted payload to the attacker through logs, processing artifacts, or other unencrypted contexts.
The vendor's extended release notes for SEPPmail version 15.0, available at https://downloads.seppmail.com/extrelnotes/150/ERN15.0.html#seppmail-vulnerability-disclosure, disclose the vulnerability and detail mitigation measures, recommending an upgrade to version 15.0.1 or later to address the issue.
Details
- CWE(s)