CVE-2026-29135: SEPPmail Secure Email Gateway before version 15.0.3 allows an attacker to craft a password-tag that bypasses s

Q: How do I fix CVE-2026-29135?

secure email gateway: upgrade to 15.0.3. Exact commands for each OS are on this page.

Q: Is CVE-2026-29135 being exploited?

CVE-2026-29135 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-29135 affect?

CVE-2026-29135 affects secure email gateway. Severity is high (CVSS 7.5). SEPPmail Secure Email Gateway before version 15.0.3 allows an attacker to craft a password-tag that bypasses subject sanitization.

Q: How urgent is CVE-2026-29135?

Priority 35/100. High severity; Remotely exploitable, no login, no user action

Routine

HIGH 7.5REMOTEUPGRADE

CVE-2026-29135 is a high-severity flaw (CVSS 7.5) affecting secure email gateway. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

SEPPmail Secure Email Gateway before version 15.0.3 allows an attacker to craft a password-tag that bypasses subject sanitization.

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.3% (top 83%)
CISA exploited list	No
Weakness	CWE-20
Published	2026-04-02
Last modified	2026-10-26

Publisher (CNA): Switzerland Government Common Vulnerability Program · Vendor: seppmail

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-02 09:16 UTCPublished CVE record published
2026-10-26 21:10 UTCUpdated Record last modified

seppmail secure email gateway UPGRADE

Affected: < 15.0.3

Fixed in: 15.0.3

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy secure-email-gateway || rpm -q secure-email-gateway || secure-email-gateway --version

2. UPGRADE to 15.0.3 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade secure-email-gateway

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade secure-email-gateway

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-29135?

secure email gateway: upgrade to 15.0.3. Exact commands for each OS are on this page.

Is CVE-2026-29135 being exploited?

CVE-2026-29135 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-29135 affect?

CVE-2026-29135 affects secure email gateway. Severity is high (CVSS 7.5). SEPPmail Secure Email Gateway before version 15.0.3 allows an attacker to craft a password-tag that bypasses subject sanitization.

How urgent is CVE-2026-29135?

Priority 35/100. High severity; Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-29139 CRITICAL 9.8 UPGRADE SEPPmail Secure Email Gateway before version 15.0.3 allows account takeover by abusing GINA account initializa
CVE-2026-29143 CRITICAL 9.1 UPGRADE SEPPmail Secure Email Gateway before version 15.0.3 does not properly authenticate the inner message of S/MIME
CVE-2026-29133 CRITICAL 9.1 UPGRADE SEPPmail Secure Email Gateway before version 15.0.3 allows an attacker to upload PGP keys with UIDs that do no
CVE-2026-29131 HIGH 7.5 UPGRADE SEPPmail Secure Email Gateway before version 15.0.3 allows attackers with a specially crafted email address to
CVE-2026-29132 HIGH 7.5 UPGRADE SEPPmail Secure Email Gateway before version 15.0.3 allows an attacker with access to a victim's GINA account

References

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