Cyber Resilience

CVE-2026-44129

High

Published: 08 May 2026

Published
08 May 2026
Modified
18 May 2026
KEV Added
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Patch
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CVSS Score v4 8.3 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:L/VA:L/SC:N/SI:N/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 0.0053 41.1th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-44129 is a high-severity Improper Neutralization of Special Elements Used in a Template Engine (CWE-1336) vulnerability in Seppmail (inferred from references). Its CVSS base score is 8.3 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 41.1th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

SEPPmail Secure Email Gateway before version 15.0.4 contains a server-side template injection vulnerability in the new GINA UI because an endpoint accepts attacker-controlled template, allowing remote attackers to execute arbitrary template expressions and potentially achieve remote code execution depending on…

more

the enabled template plugins.

CWE(s)
CWE-1336

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 →
T1059.001 PowerShell Execution
Adversaries may abuse PowerShell commands and scripts for execution.
attack.mitre.org →
Why these techniques?

SSTI in public-facing email gateway directly enables remote exploitation (T1190) and arbitrary code execution via template expressions (T1059.001).

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

CVEs Like This One

CVE-2025-53909Shared CWE-1336
CVE-2026-34587Shared CWE-1336
CVE-2022-23851Shared CWE-1336
CVE-2025-49828Shared CWE-1336
CVE-2026-21448Shared CWE-1336
CVE-2026-9558Shared CWE-1336
CVE-2025-59340Shared CWE-1336
CVE-2026-28784Shared CWE-1336
CVE-2025-64087Shared CWE-1336
CVE-2026-27961Shared CWE-1336

Affected Assets

Seppmail
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inferred from references and description; NVD did not file a CPE for this CVE

Mitigating Controls

No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.

References