CVE-2026-27442

Critical

Published: 04 March 2026

Published

04 March 2026

Modified

05 March 2026

KEV Added

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Patch

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CVSS Score v4 9.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Score 0.0042 33.5th percentile

Risk Priority 70 floored blend · peak EPSS

Summary

CVE-2026-27442 is a critical-severity Path Traversal (CWE-22) vulnerability in Seppmail Seppmail. Its CVSS base score is 9.3 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 33.5th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-2 (Flaw Remediation).

Deeper analysis

CVE-2026-27442 is a path traversal vulnerability (CWE-22) in the GINA web interface of SEPPmail Secure Email Gateway versions prior to 15.0.1. The flaw arises from insufficient validation of attachment filenames in GINA-encrypted emails, which allows attackers to access arbitrary files on the gateway server. Published on 2026-03-04, it 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 and no prerequisites for exploitation.

A remote, unauthenticated attacker can exploit this vulnerability by sending or submitting GINA-encrypted emails with specially crafted attachment filenames that traverse directory paths. No user interaction is required, and the low attack complexity enables straightforward exploitation over the network. Successful attacks grant read access to sensitive files on the gateway, such as configuration files or other system resources, without impacting integrity or availability.

The SEPPmail extended release notes for version 15.0, available at https://downloads.seppmail.com/extrelnotes/150/ERN15.0.html#seppmail-vulnerability-disclosure, disclose the vulnerability. Mitigation requires upgrading to SEPPmail Secure Email Gateway version 15.0.1 or later, which properly enforces attachment filename checks in the GINA web interface.

OWASP Top 10 for Web (2025)

EU & UK References

🇪🇺 ENISA EUVD: EUVD-2026-9378

Vulnerability details

The GINA web interface in SEPPmail Secure Email Gateway before version 15.0.1 does not properly check attachment filenames in GINA-encrypted emails, allowing an attacker to access files on the gateway.

CWE(s): CWE-22

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access

Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.

attack.mitre.org →

T1005 Data from Local System Collection

Adversaries may search local system sources, such as file systems, configuration files, local databases, virtual machine files, or process memory, to find files of interest and sensitive data prior to Exfiltration.

attack.mitre.org →

Why these techniques?

Path traversal in the exposed GINA web interface directly enables T1190 (Exploit Public-Facing Application) for unauthenticated remote file access; the resulting arbitrary local file read maps to T1005 (Data from Local System) for collection of configuration or sensitive resources.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0