CVE-2019-11739

Name: CVE-2019-11739
Creator: NVD / NIST
Published: 2019-09-27T18:15:11.677+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 0.90%

Last modified Jun 17, 2026

CVE-2019-11739 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. Encrypted S/MIME parts in a crafted multipart/alternative message can leak plaintext when included in a a HTML reply/forward. This vulnerability affects Thunderbird < 68.1 and Thunderbird < 60.9.. EPSS estimates a 0.90% chance of exploitation in the next 30 days.

Description

Encrypted S/MIME parts in a crafted multipart/alternative message can leak plaintext when included in a a HTML reply/forward. This vulnerability affects Thunderbird < 68.1 and Thunderbird < 60.9.

Metrics

CVSS 3.1

6.5/10

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

EPSS Probability

0.90%

55.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-319

Affected Software

Vendor	Product	Versions
Mozilla	Thunderbird	< 60.9.0
Mozilla	Thunderbird	>= 68.0, < 68.1.0

References

http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00009.html
http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00010.html
https://bugzilla.mozilla.org/show_bug.cgi?id=1571481Issue Tracking, Permissions Required, Vendor Advisory
https://usn.ubuntu.com/4150-1/
https://www.mozilla.org/security/advisories/mfsa2019-29/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2019-30/Vendor Advisory
http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00009.html
http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00010.html
https://bugzilla.mozilla.org/show_bug.cgi?id=1571481Issue Tracking, Permissions Required, Vendor Advisory
https://usn.ubuntu.com/4150-1/
https://www.mozilla.org/security/advisories/mfsa2019-29/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2019-30/Vendor Advisory

Timeline

Published: Sep 27, 2019
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2019-11739?

Encrypted S/MIME parts in a crafted multipart/alternative message can leak plaintext when included in a a HTML reply/forward. This vulnerability affects Thunderbird < 68.1 and Thunderbird < 60.9.

How severe is CVE-2019-11739?

CVE-2019-11739 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 0.90% probability of exploitation in the next 30 days.

How do I fix CVE-2019-11739?

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-2019-11739?

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

Scan your code now

Source: NVD / NIST