RHSA-2021:1193 — Security Advisory
Red Hat Security Advisory: thunderbird security update
Severity
ModerateRed Hat Product Security
Products
Official CSAF product identity
Published · April 14, 2021
Updated · November 22, 2025
Topic
An update for thunderbird is now available for Red Hat Enterprise Linux 8.
Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.
Description
Mozilla Thunderbird is a standalone mail and newsgroup client.
This update upgrades Thunderbird to version 78.9.1.
Security Fix(es):
-
Mozilla: An attacker may use Thunderbird's OpenPGP key refresh mechanism to poison an existing key (CVE-2021-23991)
-
Mozilla: A crafted OpenPGP key with an invalid user ID could be used to confuse the user (CVE-2021-23992)
-
Mozilla: Inability to send encrypted OpenPGP email after importing a crafted OpenPGP key (CVE-2021-23993)
For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.