CVE-2020-15955 json
In s/qmail through 4.0.07, an active MitM can inject arbitrary plaintext commands into a STARTTLS encrypted session between an SMTP client…
published 2021-08-17 5 y ago modified 2026-06-17 4 mo ago also EUVD-2020-7926
- cvss
- 5.9
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.9%
- EPSS 0.9% chance of exploitation in 30 days, percentile 61%
- public exploits
- 0
- none known
Summary
In s/qmail through 4.0.07, an active MitM can inject arbitrary plaintext commands into a STARTTLS encrypted session between an SMTP client and s/qmail. This allows e-mail messages and user credentials to be sent to the MitM attacker.
Patch / fix
- fehcom.de/sqmail/sqmail.html advisory
Exploit prediction
0.95% chance of exploitation in the next 30 days, higher than 61% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 5.9 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N |
| NVD | 2.0 | 4.3 | AV:N/AC:M/Au:N/C:P/I:N/A:N |
Classification
- Weakness
-
- CWE-77 Improper Neutralization of Special Elements used in a Command
References
-
fehcom.de
/sqmail/sqmail.html
patch, release-notes, vendor-advisory
-
nostarttls.secvuln.info
/
technical-description, third-party-advisory
Sources
- CVE List CVE-2020-15955
- NVD CVE-2020-15955
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.