Summary
It was discovered that pyOpenSSL incorrectly handled exceptions in the
tlsext_servername callback. This could result in connections being
accepted after an exception, contrary to expectations. (CVE-2026-27448)
It was discovered that pyOpenSSL incorrectly handled the DTLS cookie
generation callback. If a callback provided cookie values greater than 256
bytes, an attacker could use this issue to cause pyOpenSSL to crash,
resulting in a denial of service, or possibly execute arbitrary code. This
issue only affected Ubuntu 24.04 LTS and Ubuntu 25.10. (CVE-2026-27459)
Fixed packages 3
| Release | Package | Fixed in |
|---|---|---|
| Ubuntu · 22.04 LTS 22.04:LTS | pyopenssl | 21.0.0-1ubuntu0.1 |
| Ubuntu · 24.04 LTS 24.04:LTS | pyopenssl | 23.2.0-1ubuntu0.1 |
| Ubuntu · 25.10 | pyopenssl | 25.0.0-1ubuntu0.1 |