CVE-2026-44129Network attack vector

Unauthenticated template expression execution via untrusted input

Published May 8, 2026 · Updated May 8, 2026

Server-side template injection in SEPPmail Secure Email Gateway before 15.0.4 allows remote attackers to execute template expressions. An endpoint in the new GINA UI accepts attacker-controlled template content and evaluates its expressions rather than treating the content as data. Reaching the endpoint requires GINA v2 to be enabled; enabled template plugins determine whether expression execution extends to remote code execution.

CVSS severity8.3
High
EPSS probability0.53%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Server-side template injection in SEPPmail Secure Email Gateway before 15.0.4 allows remote attackers to execute template expressions. An endpoint in the new GINA UI accepts attacker-controlled template content and evaluates its expressions rather than treating the content as data. Reaching the endpoint requires GINA v2 to be enabled; enabled template plugins determine whether expression execution extends to remote code execution.

The record

CVE
CVE-2026-44129
Published
May 8, 2026
Updated
May 8, 2026
Vendor
SEPPmail
Product
Secure Email Gateway
Classifications
CWE-1336, CAPEC-101, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 8, 2026CVE publishedPublication date reported by the CVE source.
  2. May 8, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <15.0.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

SEPPmail · Secure Email Gatewayversion=0 <15.0.4

Published CVSS scores

8.3Switzerland Government Common Vulnerability ProgramCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:L/VA:L/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-1336Improper Neutralization of Special Elements Used in a Template Engine
CAPEC-101Server Side Include (SSI) Injection
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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