CVE-2020-28896

Name: CVE-2020-28896
Creator: NVD / NIST
Published: 2020-11-23T19:15:11.413+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.3/10EPSS 2.32%

Last modified Jun 17, 2026

CVE-2020-28896 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. Mutt before 2.0.2 and NeoMutt before 2020-11-20 did not ensure that $ssl_force_tls was processed if an IMAP server's initial server response was invalid. The connection was not properly closed, and the code could continue attempting to authenticate. EPSS estimates a 2.32% chance of exploitation in the next 30 days.

Description

Mutt before 2.0.2 and NeoMutt before 2020-11-20 did not ensure that $ssl_force_tls was processed if an IMAP server's initial server response was invalid. The connection was not properly closed, and the code could continue attempting to authenticate. This could result in authentication credentials being exposed on an unencrypted connection, or to a machine-in-the-middle.

Metrics

CVSS 3.1

5.3/10

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N

EPSS Probability

2.32%

81.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Mutt	Mutt	< 2.0.2
Neomutt	Neomutt	< 2020-11-20
Debian	Debian Linux	9.0

References

https://github.com/neomutt/neomutt/commit/9c36717a3e2af1f2c1b7242035455ec8112b4b06Patch, Third Party Advisory
https://github.com/neomutt/neomutt/releases/tag/20201120Release Notes, Third Party Advisory
https://gitlab.com/muttmua/mutt/-/commit/04b06aaa3e0cc0022b9b01dbca2863756ebbf59aPatch, Third Party Advisory
https://gitlab.com/muttmua/mutt/-/commit/d92689088dfe80a290ec836e292376e2d9984f8fPatch, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/11/msg00048.htmlMailing List, Third Party Advisory
https://security.gentoo.org/glsa/202101-32Third Party Advisory
https://github.com/neomutt/neomutt/commit/9c36717a3e2af1f2c1b7242035455ec8112b4b06Patch, Third Party Advisory
https://github.com/neomutt/neomutt/releases/tag/20201120Release Notes, Third Party Advisory
https://gitlab.com/muttmua/mutt/-/commit/04b06aaa3e0cc0022b9b01dbca2863756ebbf59aPatch, Third Party Advisory
https://gitlab.com/muttmua/mutt/-/commit/d92689088dfe80a290ec836e292376e2d9984f8fPatch, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/11/msg00048.htmlMailing List, Third Party Advisory
https://security.gentoo.org/glsa/202101-32Third Party Advisory

Timeline

Published: Nov 23, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-28896?

How severe is CVE-2020-28896?

CVE-2020-28896 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 2.32% probability of exploitation in the next 30 days.

How do I fix CVE-2020-28896?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-28896?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST