CVE-2026-29144
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedSEPPmail Secure Email Gateway before version 15.0.3 allows an attacker to bypass subject sanitization and forge security tags using Unicode lookalike characters.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceSEPPmail Secure Email Gateway before version 15.0.3 contains a vulnerability where Unicode homoglyphs (lookalike characters from different Unicode scripts) can be used to bypass subject line sanitization and forge security tags. This enables attackers to craft deceptive email subjects that appear trustworthy but contain malicious Unicode characters.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 15.0.3CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify SEPPmail Secure Email Gateway versionAccess the admin web interface or run the command-line tool to retrieve the installed SEPPmail version (typically via 'seppmail --version' or through System > Status in the web UI)Affected if The displayed version is below 15.0.3
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Confirm subject sanitization feature is activeCheck the email security policy configuration in the admin interface under Content Security or Security Tags settings to verify that subject line sanitization is enabledAffected if Subject line sanitization or security tag enforcement is turned on in the configuration
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Inspect email processing logs for suspicious UnicodeReview email gateway logs for subjects containing mixed Unicode scripts or lookalike characters (such as Cyrillic letters that resemble Latin characters) that may indicate exploitation attemptsAffected if Logs show emails with homoglyph characters in subject lines that bypassed sanitization
You are affected if your SEPPmail Secure Email Gateway version is below 15.0.3 and subject line sanitization with security tags is enabled in your configuration.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped15.0.3
Upgrade to SEPPmail Secure Email Gateway version 15.0.3 or later, which implements proper Unicode normalization and homoglyph detection in subject sanitization logic.
15.0.3
- Verify current SEPPmail Secure Email Gateway version by accessing the admin console or checking system information
- Download SEPPmail Secure Email Gateway version 15.0.3 from the official vendor download source (downloads.seppmail.com)
- Review vendor release notes and upgrade documentation for version 15.0.3
- Create a backup of current configuration and verify backup integrity
- Schedule maintenance window as upgrade may require brief service interruption
- Execute upgrade process following vendor-provided installation instructions
- After upgrade, verify the system is operational and the new version (15.0.3) is correctly installed
- Test that Unicode characters in email subjects are properly sanitized and security tags cannot be forged
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation3.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,800.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-29144 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-29144 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data