Description
An attacker may perform a DoS attack to prevent a user from sending encrypted email to a correspondent. If an attacker creates a crafted OpenPGP key with a subkey that has an invalid self signature, and the Thunderbird user imports the crafted key, then Thunderbird may try to use the invalid subkey, but the RNP library rejects it from being used, causing encryption to fail. This vulnerability affects Thunderbird < 78.9.1.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Thunderbird | unspecified – < 78.9.1 | 78.9.1 |
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 | 1:78.10.0-1 | — |
| Debian 13 | thunderbird | 1:78.10.0-1 | — |
| Debian 12 | thunderbird | 1:78.10.0-1 | — |
| Debian 10 | thunderbird | 1:78.10.0-1~deb10u1 | DSA-4897-1 |
| Debian 9 | thunderbird | 1:78.10.0-1~deb9u1 | DLA-2632-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | thunderbird | 1:78.11.0+build1-0ubuntu0.20.04.2 | USN-4995-1 |
| Ubuntu 18.04 LTS | thunderbird | 1:78.11.0+build1-0ubuntu0.18.04.2 | USN-4995-2 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8 | thunderbird | 78.9.1-1.el8_3 | RHSA-2021:1193 |
| RHEL 7 | thunderbird | 78.9.1-1.el7_9 | RHSA-2021:1192 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8.2 EUS | thunderbird | 78.9.1-1.el8_2 | RHSA-2021:1201 |
| RHEL 8.1 EUS | thunderbird | 78.9.1-1.el8_1 | RHSA-2021:1190 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | MozillaThunderbird | 91.1.1-1.1 | openSUSE-SU-2024:10601-1 |
| openSUSE Leap 15.2 | MozillaThunderbird | 78.9.1-lp152.2.38.1 | openSUSE-SU-2021:0580-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | thunderbird | 78.10.0-1.amzn2.0.1 | ALAS2-2021-1644 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 8 | thunderbird | 78.9.1-1.0.1.el8_3 | ELSA-2021-1193 |
| Oracle Linux 7 | thunderbird | 78.9.1-1.0.1.el7_9 | ELSA-2021-1192 |
Advisories 13
- RHSA-2021:1192 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- USN-4995-2 thunderbird vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- USN-4995-1 thunderbird vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- DSA-4897-1 thunderbird - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-2632-1 thunderbird - security update Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2021:0580-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Feb 4, 2026
- RHSA-2021:1201 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2021:1193 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2021:1190 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
- ALAS2-2021-1644 Important: thunderbird security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · May 24, 2021
- ELSA-2021-1193 Moderate: thunderbird security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Apr 15, 2021
- ELSA-2021-1192 Moderate: thunderbird security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Apr 15, 2021