Cyber Resilience

CVE-2026-2746

Medium

Published: 04 March 2026

Published
04 March 2026
Modified
05 March 2026
KEV Added
Patch
CVSS Score v4 6.9 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/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 0.0016 5.2th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-2746 is a medium-severity Improper Verification of Cryptographic Signature (CWE-347) vulnerability in Seppmail Seppmail. Its CVSS base score is 6.9 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Email Spoofing (T1684.002); ranked at the 5.2th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability details

SEPPmail Secure Email Gateway before version 15.0.1 does not properly communicate PGP signature verification results, leaving users unable to detect forged emails.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1684.002 Email Spoofing Stealth
Adversaries may fake, or spoof, a sender’s identity by modifying the value of relevant email headers in order to establish contact with victims under false pretenses.
Why these techniques?

CWE-347 signature verification failure in email gateway directly enables undetected email forgery/spoofing (T1672).

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

Affected Assets

seppmail
seppmail
≤ 15.0.1

Mitigating Controls

Likely Mitigating Controls AI

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.

addresses: CWE-347

Requires verification of digital signatures using organization-approved certificates before installation, directly preventing improper verification of cryptographic signatures.

addresses: CWE-347

Component authenticity commonly depends on cryptographic signatures; the control enforces proper verification of those signatures.

addresses: CWE-347

PKI certificates under an approved policy require cryptographic signature verification on issuance and validation.

addresses: CWE-347

Requires cryptographic signatures on authoritative data and support for verifying the chain of trust.

addresses: CWE-347

Mandates verification of cryptographic signatures (e.g., DNSSEC RRSIG) on resolution responses, addressing missing or bypassed signature checks.

addresses: CWE-347

Integrity tools commonly rely on cryptographic signatures whose improper validation this weakness covers.

addresses: CWE-347

Authenticity validation commonly relies on cryptographic signature or certificate checks that this control enforces.

References