Description
The S/MIME specification allows a Cipher Block Chaining (CBC) malleability-gadget attack that can indirectly lead to plaintext exfiltration, aka EFAIL.
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 | evolution | No fix yet | — |
| Debian 13 | evolution | No fix yet | — |
| Debian 12 | evolution | No fix yet | — |
| Debian 12 | kf5-messagelib | 4:18.08.1-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | thunderbird | 1:52.8.0+build1-0ubuntu0.18.04.1 | — |
| Ubuntu 16.04 LTS | thunderbird | 1:52.8.0+build1-0ubuntu0.16.04.1 | — |
| Ubuntu 14.04 LTS | thunderbird | 1:52.8.0+build1-0ubuntu0.14.04.1 | — |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 20.04 LTS | kmail | 4:19.12.3-0ubuntu1+esm1 | USN-7731-1 |
| Ubuntu Pro 18.04 LTS | kf5-messagelib | 4:17.12.3-0ubuntu3+esm1 | USN-7730-1 |
| Ubuntu Pro 18.04 LTS | kmail | 4:17.12.3-0ubuntu1+esm1 | USN-7731-1 |
| Ubuntu Pro 16.04 LTS | kdepim | 4:15.12.3-0ubuntu1.1+esm1 | USN-7729-1 |
| Ubuntu Pro 14.04 LTS | kdepim | 4:4.13.3-0ubuntu0.2+esm1 | USN-7729-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SUSE Package Hub 12 | enigmail | 2.0.4-9.1 | openSUSE-SU-2018:1330-1, openSUSE-SU-2018:1329-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | enigmail | 2.2.4-1.4 | openSUSE-SU-2024:10736-1 |
Advisories 7
- USN-7729-1 kdepim vulnerabilities Ubuntu Security Notices (USN) · Jun 25, 2026
- USN-7730-1 kf5-messagelib vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- USN-7731-1 kmail vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- openSUSE-SU-2024:10736-1 enigmail-2.2.4-1.4 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2018:1329-1 Security update for enigmail SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2018:1330-1 Security update for enigmail SUSE / openSUSE Security Updates · Feb 4, 2026
- WID-SEC-2025-1949 S/MIME und OpenPGP verschlüsselten Mails: Schwachstelle ermöglicht Entschlüsselung BSI CERT-Bund (WID) · Sep 7, 2025