Cyber Resilience

CVE-2026-29131

Seppmail Secure Email Gateway ≤ 15.0.3

Published
02 April 2026
Modified
16 April 2026
CVSS Score v4 4.9
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:N/SC:H/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 0.0023 13th percentile
Risk Priority 31 floored blend · peak EPSS

Summary

CVE-2026-29131 is a medium-severity LDAP Injection (CWE-90) vulnerability in Seppmail Secure Email Gateway. Its CVSS base score is 4.9 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 13th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-29131 is a vulnerability in SEPPmail Secure Email Gateway versions prior to 15.0.3 that enables attackers to read the contents of emails encrypted for other users by using a specially crafted email address. This issue, associated with CWE-90 (Improper Neutralization of Special Elements used in an SQL Command), 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.

The vulnerability can be exploited remotely by unauthenticated attackers who send an email containing the specially crafted address to the affected gateway. Successful exploitation allows the attacker to access sensitive email content intended for other recipients, potentially exposing confidential information without impacting integrity or availability.

SEPPmail's release notes for version 15.0 document the vulnerability disclosure and confirm that upgrading to version 15.0.3 resolves the issue. Security practitioners should apply this update promptly to affected installations.

OWASP Top 10 for Web (2025)

A05:2025 Injection

EU & UK References

Vulnerability Data

SEPPmail Secure Email Gateway before version 15.0.3 allows attackers with a specially crafted email address to read the contents of emails encrypted for other users.

CWE(s)
CWE-90

Related Threats

MITRE ATT&CK Enterprise Techniques

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 →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-29138Same product: Seppmail Secure Email Gateway
CVE-2026-29132Same product: Seppmail Secure Email Gateway
CVE-2026-29134Same product: Seppmail Secure Email Gateway
CVE-2026-29139Same product: Seppmail Secure Email Gateway
CVE-2026-29136Same product: Seppmail Secure Email Gateway
CVE-2026-29143Same product: Seppmail Secure Email Gateway
CVE-2026-29141Same product: Seppmail Secure Email Gateway
CVE-2026-29135Same product: Seppmail Secure Email Gateway
CVE-2026-29144Same product: Seppmail Secure Email Gateway
CVE-2026-29137Same product: Seppmail Secure Email Gateway

Affected Assets

seppmail
secure email gateway
≤ 15.0.3

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V1.2.6

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation can discover LDAP injection flaws through static analysis or crafted test cases.

SI-10 Information Input Validation good match

Input validation directly stops untrusted data from reaching an LDAP query builder without neutralization of special characters.

SA-8 Security and Privacy Engineering Principles partial match

Secure engineering principles require safe query construction and escaping that structurally prevents LDAP injection.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require input neutralization and query parameterization to prevent LDAP injection.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development catches LDAP injection via dynamic analysis or fuzzing, but does not prevent it at the source.

A.8.25 Secure development life cycle partial match
prevents

Secure development lifecycle mandates input validation and query construction practices that directly prevent LDAP injection.

A.8.26 Application security requirements partial match
prevents

Application security requirements include explicit rules for safe construction of directory queries, mitigating LDAP injection.

A.8.28 Secure coding partial match
prevents

Secure coding standards require proper neutralization of LDAP special characters, directly eliminating this weakness.

A.8.27 Secure system architecture and engineering principles none match
mitigates

Secure architecture principles encourage safe query interfaces but do not prescribe the specific coding controls needed for LDAP injection.

A.8.3 Information access restriction none match
none

Information access restriction limits who can query LDAP but does not address how queries are built.

References