CVE-2020-14954

What it is

Mutt before 1.14.4 and NeoMutt before 2020-06-19 have a STARTTLS buffering issue that affects IMAP, SMTP, and POP3. When a server sends a "begin TLS" response, the client reads additional data (e.g., from a man-in-the-middle attacker) and evaluates it in a TLS context, aka "response injection."

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data tampering.

Exploit odds

2.3% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2020-06-21 17:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 02:55 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 2.3% in the next 30 days (EPSS).
• Severity: 5.9 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2020-06-21 17:15 UTC

Last modified

2026-06-17 02:55 UTC

Exploit probability

2.3% · EPSS, next 30 days

Weakness

CWE-74

Record status

Modified

Affected

• Mutt < 1.14.4
• Debian Linux 9.0
• Debian Linux 10.0
• Neomutt < 20200619
• Fedoraproject Fedora 31
• Fedoraproject Fedora 32
• Debian Linux 8.0
• Canonical Ubuntu Linux 12.04

Attack profile CVSS 3.1 · 5.9

Attack vector

Network

Complexity

High

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

High

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2020-14954.md and follow it. Check whether this project is affected by CVE-2020-14954. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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