Description
Botan before 3.6.0, when certain GCC versions are used, has a compiler-induced secret-dependent operation in lib/utils/donna128.h in donna128 (used in Chacha-Poly1305 and x25519). An addition can be skipped if a carry is not set. This was observed for GCC 11.3.0 with -O2 on MIPS, and GCC on x86-i386. (Only 32-bit processors can be affected.)
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 | 2.19.5+dfsg-3 | — |
| Debian 12 | botan | 2.19.3+dfsg-1+deb12u1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | oscar | No fix yet | — |
| Ubuntu 26.04 LTS | oscar | No fix yet | — |
| Ubuntu 25.10 | oscar | No fix yet | — |
| Ubuntu 24.04 LTS | oscar | No fix yet | — |
| Ubuntu 22.04 LTS | oscar | No fix yet | — |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | botan +1 | No fix yet | — |
| Ubuntu 18.04 LTS | botan | No fix yet | — |
| Ubuntu Pro 24.04 LTS | botan | 2.19.3+dfsg-1ubuntu2+esm1 | USN-7586-1 |
| Ubuntu Pro 22.04 LTS | botan | 2.19.1+dfsg-2ubuntu1+esm1 | USN-7586-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SUSE Package Hub 15 SP6 | Botan | 2.19.5-bp156.3.6.1 | openSUSE-SU-2024:0343-1 |
| SUSE Package Hub 15 SP5 | Botan | 2.19.5-bp156.3.6.1 | openSUSE-SU-2024:0343-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 15.6 | Botan | 2.19.5-bp156.3.6.1 | openSUSE-SU-2024:0343-1 |
| openSUSE Leap 15.5 | Botan | 2.19.5-bp156.3.6.1 | openSUSE-SU-2024:0343-1 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | botan2 | No fix yet | — |
| Azure Linux 2 (CBL-Mariner) | botan2 | No fix yet | — |
Advisories 2
- USN-7586-1 botan vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- openSUSE-SU-2024:0343-1 Security update for Botan SUSE / openSUSE Security Updates · Feb 4, 2026