HOMEVULNERABILITIESCVE-2020-14954
MEDIUM

CVE-2020-14954

CWE-74Published: June 21, 2020· Updated: Jun 17, 2026

5.9
CVSS v3.1

Official Description

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."

NVD Source

Technical Analysis

CVE-2020-14954 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in full integrity compromise (data manipulation), with a CVSS base score of 5.9.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityHigh
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityHigh
AvailabilityNone
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N

Affected Vendors & Products

Canonical1 product(s)
ubuntu linux
Debian1 product(s)
debian linux
Fedora1 product(s)
fedora
mutt1 product(s)
mutt
neomutt1 product(s)
neomutt
openSUSE1 product(s)
leap
Source: NVD CPE · 14 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttps://github.com/neomutt/neomutt/commit/fb013ec666759cb8a9e294347c7b4c1f597639cc
PATCHhttps://gitlab.com/muttmua/mutt/-/commit/c547433cdf2e79191b15c6932c57f1472bfb5ff4
PATCHhttps://github.com/neomutt/neomutt/commit/fb013ec666759cb8a9e294347c7b4c1f597639cc
PATCHhttps://gitlab.com/muttmua/mutt/-/commit/c547433cdf2e79191b15c6932c57f1472bfb5ff4
ADVISORYhttp://lists.mutt.org/pipermail/mutt-announce/Week-of-Mon-20200615/000023.html
ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2020-06/msg00064.html
ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2020-06/msg00070.html
ADVISORYhttps://gitlab.com/muttmua/mutt/-/issues/248
ADVISORYhttps://lists.debian.org/debian-lts-announce/2020/06/msg00039.html
ADVISORYhttps://lists.debian.org/debian-lts-announce/2020/06/msg00040.html
ADVISORYhttps://security.gentoo.org/glsa/202007-57
ADVISORYhttps://usn.ubuntu.com/4403-1/
ADVISORYhttps://www.debian.org/security/2020/dsa-4707
ADVISORYhttps://www.debian.org/security/2020/dsa-4708
ADVISORYhttp://lists.mutt.org/pipermail/mutt-announce/Week-of-Mon-20200615/000023.html
ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2020-06/msg00064.html
ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2020-06/msg00070.html
ADVISORYhttps://gitlab.com/muttmua/mutt/-/issues/248
ADVISORYhttps://lists.debian.org/debian-lts-announce/2020/06/msg00039.html
ADVISORYhttps://lists.debian.org/debian-lts-announce/2020/06/msg00040.html
ADVISORYhttps://security.gentoo.org/glsa/202007-57
ADVISORYhttps://usn.ubuntu.com/4403-1/
ADVISORYhttps://www.debian.org/security/2020/dsa-4707
ADVISORYhttps://www.debian.org/security/2020/dsa-4708

All References (32)

→
http://lists.mutt.org/pipermail/mutt-announce/Week-of-Mon-20200615/000023.htmlMailing List · Vendor Advisory
→
http://lists.opensuse.org/opensuse-security-announce/2020-06/msg00064.htmlThird Party Advisory
→
http://lists.opensuse.org/opensuse-security-announce/2020-06/msg00070.htmlThird Party Advisory
→
http://www.mutt.org/Product
→
https://github.com/neomutt/neomutt/commit/fb013ec666759cb8a9e294347c7b4c1f597639ccPatch
→
https://github.com/neomutt/neomutt/releases/tag/20200619Release Notes
→
https://gitlab.com/muttmua/mutt/-/commit/c547433cdf2e79191b15c6932c57f1472bfb5ff4Patch
→
https://gitlab.com/muttmua/mutt/-/issues/248Issue Tracking · Third Party Advisory
→
https://lists.debian.org/debian-lts-announce/2020/06/msg00039.htmlMailing List · Third Party Advisory
→
https://lists.debian.org/debian-lts-announce/2020/06/msg00040.htmlMailing List · Third Party Advisory
→
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EFMEILCBKMZRRZDMUGWLVN4PQQ4VTAZE/
→
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/K3LXFVPTLK4PNHL6MPKJNJQJ25CH7GLQ/
→
https://security.gentoo.org/glsa/202007-57Third Party Advisory
→
https://usn.ubuntu.com/4403-1/Third Party Advisory
→
https://www.debian.org/security/2020/dsa-4707Third Party Advisory

Quick Facts

CVE IDCVE-2020-14954
CVSS Score5.9 / 10
SeverityMEDIUM
WeaknessCWE-74
CISA KEVNo
Affected6 vendor(s)
PublishedJun 21, 2020

Related CVEs (CWE-74)

CVE-2026-44182
10.0
CVE-2025-20265
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CVE-2023-30547
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CVE-2023-1523
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CVE-2026-56699
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CVE-2020-26282
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Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2020-14954 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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