RHSA-2021:1201 — Security Advisory

Red Hat Security Advisory: thunderbird security update

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Severity

Moderate

Red Hat Product Security

RHEL 8

Products

Official CSAF product identity

Published · April 15, 2021

Updated · November 22, 2025

Topic

An update for thunderbird is now available for Red Hat Enterprise Linux 8.2 Extended Update Support.

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.

Related CVEs

RHSA-2021:1201 — Red Hat Security Advisory: thunderbird security update | PulseLinux