CVE-2019-10741: K-9 Mail v5.600 can include the original quoted HTML code of a specially crafted, benign looking, email within

Routine

MEDIUM 4.3DOWNGRADE

CVE-2019-10741 is a medium-severity flaw (CVSS 4.3) affecting k-9 mail. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

K-9 Mail v5.600 can include the original quoted HTML code of a specially crafted, benign looking, email within (digitally signed) reply messages. The quoted part can contain conditional statements that show completely different text if opened in a different email client. This can be abused by an attacker to obtain valid S/MIME or PGP signatures for arbitrary content to be displayed to a third party. NOTE: the vendor states "We don't plan to take

Why this priority

No elevated risk signals yet

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

Risk facts

CVSS score	4.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.9% (top 40%)
CISA exploited list	No
Weakness	CWE-254
Published	2019-04-07
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: k-9 mail project

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

Am I affected?

Timeline

2019-04-07 15:29 UTCPublished CVE record published
2026-06-17 02:11 UTCUpdated Record last modified

k-9 mail project k-9 mail DOWNGRADE

Affected: 5.600

Fixed in: no fixed release known

Safe to downgrade to: a release before 5.600

1. Check installed version

apt-cache policy k-9-mail || rpm -q k-9-mail || k-9-mail --version

2. No fixed release: DOWNGRADE to a release before 5.600 (Debian / Ubuntu)

apt-cache madison k-9-mail sudo apt install k-9-mail=<VERSION_BEFORE_5.600> sudo apt-mark hold k-9-mail

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

dnf --showduplicates list k-9-mail sudo dnf downgrade k-9-mail-<VERSION_BEFORE_5.600> sudo dnf versionlock add k-9-mail

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-2019-10741?

k-9 mail: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2019-10741 being exploited?

CVE-2019-10741 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-2019-10741 affect?

CVE-2019-10741 affects k-9 mail. Severity is medium (CVSS 4.3). K-9 Mail v5.600 can include the original quoted HTML code of a specially crafted, benign looking, email within (digitally signed) reply messages. The quoted part can contain conditional statements that show completely different text if open

How urgent is CVE-2019-10741?

Priority 30/100. No elevated risk signals yet.

Related CVEs

CVE-2018-1000831 CRITICAL 10.0 UPGRADE K9Mail version <= v5.600 contains a XML External Entity (XXE) vulnerability in WebDAV response parser that can

References

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