How severe is CVE-2026-29137?

CVE-2026-29137 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.

Is CVE-2026-29137 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (9th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-29137?

CVE-2026-29137 affects Seppmail Secure Email Gateway. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-29137?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-29137 have an EU (EUVD) identifier?

Yes. CVE-2026-29137 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-18154.

When was CVE-2026-29137 published?

CVE-2026-29137 was published on 2026-04-02 and last updated on 2026-06-17.

CVE-2026-29137

CVE-2026-29137 is a medium-severity vulnerability in Seppmail Secure Email Gateway with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v4: 5.3
EPSS exploit prediction: 0% (9th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-18154
Weakness: CWE-20
Affected product: Seppmail Secure Email Gateway
Published: 2026-04-02
Last modified: 2026-06-17

Description

SEPPmail Secure Email Gateway before version 15.0.3 allows an attacker to hide security tags from users by crafting a long subject.

Frequently asked questions

What is CVE-2026-29137?: SEPPmail Secure Email Gateway before version 15.0.3 allows an attacker to hide security tags from users by crafting a long subject.
How severe is CVE-2026-29137?: CVE-2026-29137 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2026-29137 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (9th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-29137?: CVE-2026-29137 affects Seppmail Secure Email Gateway. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-29137?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-29137 have an EU (EUVD) identifier?: Yes. CVE-2026-29137 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-18154.
When was CVE-2026-29137 published?: CVE-2026-29137 was published on 2026-04-02 and last updated on 2026-06-17.

References

https://downloads.seppmail.com/extrelnotes/150/ERN15.0.html#seppmail-vulnerability-disclosure-1503

Affected products (1)

cpe:2.3:a:seppmail:secure_email_gateway:*:*:*:*:*:*:*:*

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