Description
When displaying the sender of an email, and the sender name contained the Braille Pattern Blank space character multiple times, Thunderbird would have displayed all the spaces. This could have been used by an attacker to send an email message with the attacker's digital signature, that was shown with an arbitrary sender email address chosen by the attacker. If the sender name started with a false email address, followed by many Braille space characters, the attacker's email address was not visible. Because Thunderbird compared the invisible sender address with the signature's email address, if the signing key or certificate was accepted by Thunderbird, the email was shown as having a valid digital signature. This vulnerability affects Thunderbird < 91.10.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Thunderbird | unspecified – < 91.10 | 91.10 |
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 | 1:91.10.0-1 | — |
| Debian 13 | thunderbird | 1:91.10.0-1 | — |
| Debian 12 | thunderbird | 1:91.10.0-1 | — |
| Debian 11 | thunderbird | 1:91.10.0-1~deb11u1 | DSA-5158-1 |
| Debian 10 | thunderbird | 1:91.10.0-1~deb10u1 | DSA-5158-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 9 | thunderbird | 1:91.10.0-1~deb9u1 | DLA-3041-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 22.04 LTS | thunderbird | 1:91.11.0+build2-0ubuntu0.22.04.1 | USN-5512-1 |
| Ubuntu 20.04 LTS | thunderbird | 1:91.11.0+build2-0ubuntu0.20.04.1 | USN-5512-1 |
| Ubuntu 18.04 LTS | thunderbird | 1:91.11.0+build2-0ubuntu0.18.04.1 | USN-5512-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 9 | thunderbird | 91.10.0-1.el9_0 | RHSA-2022:4892 |
| RHEL 8 | thunderbird | 91.10.0-1.el8_6 | RHSA-2022:4887 |
| RHEL 7 | thunderbird | 91.10.0-1.el7_9 | RHSA-2022:4891 |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8.4 EUS | thunderbird | 91.10.0-1.el8_4 | RHSA-2022:4889 |
| RHEL 8.2 EUS | thunderbird | 91.10.0-1.el8_2 | RHSA-2022:4890 |
| RHEL 8.1 E4S | thunderbird | 91.10.0-1.el8_1 | RHSA-2022:4888 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 8 | thunderbird | 91.10.0-1.el8_6 | RLSA-2022:4887 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP4 | MozillaThunderbird | 91.10.0-150200.8.73.1 | SUSE-SU-2022:2062-1 |
| SLES 15 SP3 | MozillaThunderbird | 91.10.0-150200.8.73.1 | SUSE-SU-2022:2062-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | MozillaThunderbird | 91.10.0-1.1 | openSUSE-SU-2024:12117-1 |
| openSUSE Leap 15.4 | MozillaThunderbird | 91.10.0-150200.8.73.1 | SUSE-SU-2022:2062-1 |
| openSUSE Leap 15.3 | MozillaThunderbird | 91.10.0-150200.8.73.1 | SUSE-SU-2022:2062-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.23 | thunderbird | 91.10.0-r0 | — |
| Alpine v3.22 | thunderbird | 91.10.0-r0 | — |
| Alpine v3.21 | thunderbird | 91.10.0-r0 | — |
| Alpine v3.20 | thunderbird | 91.10.0-r0 | — |
| Alpine v3.19 | thunderbird | 91.10.0-r0 | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.18 | thunderbird | 91.10.0-r0 | — |
| Alpine v3.17 | thunderbird | 91.10.0-r0 | — |
| Alpine v3.16 | thunderbird | 91.10.0-r0 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | thunderbird | 91.11.0-2.amzn2.0.1 | ALAS2-2022-1828 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 9 | thunderbird | 91.10.0-1.0.1.el9_0 | ELSA-2022-4892 |
| Oracle Linux 8 | thunderbird | 91.10.0-1.0.1.el8_6 | ELSA-2022-4887 |
| Oracle Linux 7 | thunderbird | 91.10.0-1.0.1.el7_9 | ELSA-2022-4891 |
Advisories 18
- RHSA-2022:4891 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- USN-5512-1 thunderbird vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- DSA-5158-1 thunderbird - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-3041-1 thunderbird - security update Debian Security (DSA / DLA) · Mar 9, 2026
- RLSA-2022:4887 Important: thunderbird security update Rocky Linux Security Advisories · Feb 5, 2026
- openSUSE-SU-2024:12117-1 MozillaThunderbird-91.10.0-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2022:2062-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Feb 4, 2026
- RHSA-2022:4892 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2022:4889 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2022:4890 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2022:4888 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2022:4887 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- WID-SEC-2022-1335 Xerox FreeFlow Print Server: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 6, 2025
- WID-SEC-2022-0019 Mozilla Firefox und Thunderbird: Mehrere Schwachstellen ermöglichen Codeausführung BSI CERT-Bund (WID) · Jul 10, 2024
- ALAS2-2022-1828 Important: thunderbird security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Jul 3, 2024
- ELSA-2022-4892 Important: thunderbird security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Jun 30, 2022
- ELSA-2022-4887 Important: thunderbird security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Jun 6, 2022
- ELSA-2022-4891 Important: thunderbird security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Jun 3, 2022