CVE-2019-8337: In msmtp 1.8.2 and mpop 1.4.3, when tls_trust_file has its default configuration, certificate-verification res

Routine

MEDIUM 5.3REMOTEDOWNGRADEDOWNGRADE

CVE-2019-8337 is a medium-severity flaw (CVSS 5.3) affecting mpop, msmtp. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

In msmtp 1.8.2 and mpop 1.4.3, when tls_trust_file has its default configuration, certificate-verification results are not properly checked.

Why this priority

Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	5.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.9% (top 40%)
CISA exploited list	No
Weakness	CWE-295
Published	2019-02-13
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: marlam

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2019-02-13 20:29 UTCPublished CVE record published
2026-06-17 02:41 UTCUpdated Record last modified

marlam mpop DOWNGRADE

Affected: 1.4.2

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.4.2

1. Check installed version

apt-cache policy mpop || rpm -q mpop || mpop --version

2. No fixed release: DOWNGRADE to a release before 1.4.2 (Debian / Ubuntu)

apt-cache madison mpop sudo apt install mpop=<VERSION_BEFORE_1.4.2> sudo apt-mark hold mpop

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list mpop sudo dnf downgrade mpop-<VERSION_BEFORE_1.4.2> sudo dnf versionlock add mpop

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

marlam msmtp DOWNGRADE

Affected: 1.8.2

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.8.2

1. Check installed version

apt-cache policy msmtp || rpm -q msmtp || msmtp --version

2. No fixed release: DOWNGRADE to a release before 1.8.2 (Debian / Ubuntu)

apt-cache madison msmtp sudo apt install msmtp=<VERSION_BEFORE_1.8.2> sudo apt-mark hold msmtp

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list msmtp sudo dnf downgrade msmtp-<VERSION_BEFORE_1.8.2> sudo dnf versionlock add msmtp

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2019-8337?

mpop: downgrade or apply the listed mitigation; msmtp: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2019-8337 being exploited?

CVE-2019-8337 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2019-8337 affect?

CVE-2019-8337 affects mpop, msmtp. Severity is medium (CVSS 5.3). In msmtp 1.8.2 and mpop 1.4.3, when tls_trust_file has its default configuration, certificate-verification results are not properly checked.

How urgent is CVE-2019-8337?

Priority 39/100. Remotely exploitable, no login, no user action

References

← Back to latest CVEs