Description
Botan 2.2.0 - 2.4.0 (fixed in 2.5.0) improperly handled wildcard certificates and could accept certain certificates as valid for hostnames when, under RFC 6125 rules, they should not match. This only affects certificates issued to the same domain as the host, so to impersonate a host one must already have a wildcard certificate matching other hosts in the same domain. For example, b*.example.com would match some hostnames that do not begin with a 'b' character.
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 13 | botan | 2.4.0-5 | — |
| Debian 12 | botan | 2.4.0-5 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | botan | No fix yet | — |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 22.04 LTS | botan | No fix yet | — |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | Botan | 2.18.1-1.3 | openSUSE-SU-2024:10594-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.21 | botan | 2.5.0-r0 | — |
| Alpine v3.20 | botan | 2.5.0-r0 | — |
| Alpine v3.19 | botan | 2.5.0-r0 | — |
| Alpine v3.18 | botan | 2.5.0-r0 | — |
| Alpine v3.17 | botan | 2.5.0-r0 | — |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.16 | botan | 2.5.0-r0 | — |
| Alpine v3.15 | botan | 2.5.0-r0 | — |
| Alpine v3.14 | botan | 2.5.0-r0 | — |
| Alpine v3.13 | botan | 2.5.0-r0 | — |
| Alpine v3.12 | botan | 2.5.0-r0 | — |
| Alpine v3.11 | botan | 2.5.0-r0 | — |
| Alpine v3.10 | botan | 2.5.0-r0 | — |
Advisories 1
- openSUSE-SU-2024:10594-1 Botan-2.18.1-1.3 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026