Datalust Seq.App.EmailPlus (aka seq-app-htmlemail) 3.1.0-dev-00148, 3.1.0-dev-00170, and 3.1.0-dev-00176 can use cleartext SMTP on port 25…

published 2021-11-02 5y ago modified 2026-06-17 4mo ago also EUVD-2021-30214

cvss: 7.5; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 32%
public exploits: 0; none known

Datalust Seq.App.EmailPlus (aka seq-app-htmlemail) 3.1.0-dev-00148, 3.1.0-dev-00170, and 3.1.0-dev-00176 can use cleartext SMTP on port 25 in some cases where encryption on port 465 was intended.

Patch / fix

links 1

github.com/datalust/seq-app-htmlemail#93 pull request

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Exploit prediction

0.38% chance of exploitation in the next 30 days, higher than 32% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by	version	score	vector
NVD	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD	2.0	5.0	AV:N/AC:L/Au:N/C:P/I:N/A:N

Classification

Weakness

CWE-319 Cleartext Transmission of Sensitive Information

References

github.com /datalust/seq-app-htmlemail/pull/93
patch, third-party-advisory

Sources

CVE List CVE-2021-43270
NVD CVE-2021-43270

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