Description
An issue was discovered in Mbed TLS 3.5.0 through 4.0.0. Client impersonation can occur while resuming a TLS 1.3 session.
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 | mbedtls | 3.6.6-0.1 | — |
| Debian 13 | mbedtls | 3.6.6-0.1~deb13u1 | — |
| Debian 12 | mbedtls | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | mbedtls | No fix yet | — |
| Ubuntu 26.04 LTS | mbedtls | No fix yet | — |
| Ubuntu 25.10 | mbedtls | No fix yet | — |
| Ubuntu 16.04 LTS | mbedtls | No fix yet | — |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 24.04 LTS | mbedtls | No fix yet | — |
| Ubuntu Pro 22.04 LTS | mbedtls | No fix yet | — |
| Ubuntu Pro 20.04 LTS | mbedtls | No fix yet | — |
| Ubuntu Pro 18.04 LTS | mbedtls | No fix yet | — |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | mbedtls | 3.6.6-1.1 | openSUSE-SU-2026:10498-1 |
Advisories 1
- openSUSE-SU-2026:10498-1 libeverest-3.6.6-1.1 on GA media SUSE / openSUSE Security Updates · Apr 8, 2026