Description
When requesting an OpenPGP key from a WKD server, an incorrect padding size was used and a network observer could have learned the length of the requested email address. This vulnerability was fixed in Thunderbird 136 and Thunderbird 128.8.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Thunderbird | — | 128.8 |
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 | 1:128.8.0esr-1 | — |
| Debian 13 | thunderbird | 1:128.8.0esr-1 | — |
| Debian 12 | thunderbird | 1:128.8.0esr-1~deb12u1 | DSA-5876-1 |
| Debian 11 | thunderbird | 1:128.8.0esr-1~deb11u1 | DLA-4081-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 22.04 LTS | thunderbird | 1:128.12.0+build1-0ubuntu0.22.04.1 | USN-7663-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 9 | thunderbird | 128.8.0-2.el9_5 | RHSA-2025:2899 |
| RHEL 8 | thunderbird | 128.8.0-2.el8_10 | RHSA-2025:2900 |
Show 11 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 9.4 EUS | thunderbird | 128.8.0-2.el9_4 | RHSA-2025:2957 |
| RHEL 9.2 EUS | thunderbird | 128.8.0-2.el9_2 | RHSA-2025:2959 |
| RHEL 9.0 E4S | thunderbird | 128.8.0-2.el9_0 | RHSA-2025:3013 |
| RHEL 8.8 EUS | thunderbird | 128.8.0-2.el8_8 | RHSA-2025:2958 |
| RHEL 8.6 TUS | thunderbird | 128.8.0-2.el8_6 | RHSA-2025:3036 |
| RHEL 8.6 E4S | thunderbird | 128.8.0-2.el8_6 | RHSA-2025:3036 |
| RHEL 8.6 AUS | thunderbird | 128.8.0-2.el8_6 | RHSA-2025:3036 |
| RHEL 8.4 TUS | thunderbird | 128.8.0-2.el8_4 | RHSA-2025:3009 |
| RHEL 8.4 E4S | thunderbird | 128.8.0-2.el8_4 | RHSA-2025:3009 |
| RHEL 8.4 AUS | thunderbird | 128.8.0-2.el8_4 | RHSA-2025:3009 |
| RHEL 8.2 AUS | thunderbird | 128.8.0-2.el8_2 | RHSA-2025:2960 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 8 | thunderbird | 128.8.0-2.el8_10.alma.1 | ALSA-2025:2900 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP6 | MozillaThunderbird | 128.8.0-150200.8.203.1 | SUSE-SU-2025:0849-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 15.6 | MozillaThunderbird | 128.8.0-150200.8.203.1 | SUSE-SU-2025:0849-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | thunderbird | 128.8.1-1.amzn2.0.1 | ALAS2-2025-2807 |
Advisories 16
- ALSA-2025:2900 Important: thunderbird security update AlmaLinux Security Advisories · Nov 6, 2026
- RHSA-2025:2959 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 28, 2026
- RHSA-2025:3009 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 28, 2026
- RHSA-2025:2899 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 28, 2026
- RHSA-2025:3036 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 28, 2026
- RHSA-2025:2900 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 28, 2026
- RHSA-2025:3013 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 28, 2026
- RHSA-2025:2957 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 28, 2026
- RHSA-2025:2958 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 28, 2026
- RHSA-2025:2960 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jul 28, 2026
- USN-7663-1 thunderbird vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- DSA-5876-1 thunderbird - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-4081-1 thunderbird - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2025:0849-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Feb 4, 2026
- WID-SEC-2025-0482 Mozilla Firefox, Mozilla Firefox ESR und Mozilla Thunderbird: Mehrere Schwachstellen BSI CERT-Bund (WID) · Feb 2, 2026
- ALAS2-2025-2807 Important: thunderbird security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Apr 1, 2025