Description
If Thunderbird is configured to use STARTTLS for an IMAP server, and the server sends a PREAUTH response, then Thunderbird will continue with an unencrypted connection, causing email data to be sent without protection. This vulnerability affects Thunderbird < 68.9.0.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Thunderbird | unspecified – < 68.9.0 | 68.9.0 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | thunderbird | 1:68.9.0-1 | — |
| Debian 13 | thunderbird | 1:68.9.0-1 | — |
| Debian 12 | thunderbird | 1:68.9.0-1 | — |
| Debian 10 | thunderbird | 1:68.9.0-1~deb10u1 | DSA-4702-1 |
| Debian 9 | thunderbird | 1:68.9.0-1~deb9u1 | DSA-4702-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 8 | thunderbird | 1:68.9.0-1~deb8u2 | DLA-2247-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | thunderbird | 1:68.10.0+build1-0ubuntu0.20.04.1 | USN-4421-1 |
| Ubuntu 18.04 LTS | thunderbird | 1:68.10.0+build1-0ubuntu0.18.04.1 | USN-4421-1 |
| Ubuntu 16.04 LTS | thunderbird | 1:68.10.0+build1-0ubuntu0.16.04.1 | USN-4421-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8 | thunderbird | 68.9.0-1.el8_2 | RHSA-2020:2614 |
| RHEL 7 | thunderbird | 68.9.0-1.el7_8 | RHSA-2020:2615 |
| RHEL 6 | thunderbird | 68.9.0-1.el6_10 | RHSA-2020:2613 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8.1 EUS | thunderbird | 68.9.0-1.el8_1 | RHSA-2020:2611 |
| RHEL 8.0 E4S | thunderbird | 68.9.0-1.el8_0 | RHSA-2020:2616 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP2 | MozillaThunderbird | 68.9.0-3.85.2 | SUSE-SU-2020:1591-2 |
| SLES 15 SP1 | MozillaThunderbird | 68.9.0-3.85.2 | SUSE-SU-2020:1591-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | MozillaThunderbird | 91.1.1-1.1 | openSUSE-SU-2024:10601-1 |
| openSUSE Leap 15.1 | MozillaThunderbird | 68.9.0-lp151.2.41.1 | openSUSE-SU-2020:0799-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.23 | thunderbird | 68.9.0-r0 | — |
| Alpine v3.22 | thunderbird | 68.9.0-r0 | — |
| Alpine v3.21 | thunderbird | 68.9.0-r0 | — |
| Alpine v3.20 | thunderbird | 68.9.0-r0 | — |
| Alpine v3.19 | thunderbird | 68.9.0-r0 | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.18 | thunderbird | 68.9.0-r0 | — |
| Alpine v3.17 | thunderbird | 68.9.0-r0 | — |
| Alpine v3.16 | thunderbird | 68.9.0-r0 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | thunderbird | 68.9.0-1.amzn2 | ALAS2-2020-1462 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 8 | thunderbird | 68.9.0-1.0.1.el8_2 | ELSA-2020-2614 |
| Oracle Linux 7 | thunderbird | 68.9.0-1.0.1.el7_8 | ELSA-2020-2615 |
Advisories 15
- RHSA-2020:2615 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2020:2613 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- USN-4421-1 thunderbird vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- DSA-4702-1 thunderbird - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-2247-1 thunderbird - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2020:1591-2 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2020:0799-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:1591-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Feb 4, 2026
- RHSA-2020:2616 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2020:2614 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2020:2611 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- openSUSE-SU-2024:10601-1 MozillaThunderbird-91.1.1-1.1 on GA media SUSE / openSUSE Security Updates · May 7, 2025
- ALAS2-2020-1462 Important: thunderbird security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Jul 17, 2020
- ELSA-2020-2614 Important: thunderbird security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Jun 23, 2020
- ELSA-2020-2615 Important: thunderbird security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Jun 22, 2020