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 )
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 )
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 )
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 )
In general, a standard system update will make all the necessary changes.
The problem can be corrected by updating your system to the following package versions:
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The full story
This article is one source in a clustered incident — the cluster page carries the summary, timeline and every other outlet covering it.
