> USN-8155-1: OpenSSL vulnerabilities

Viktor Dukhovni discovered that OpenSSL incorrectly negotiated the expected preferred key exchange group when used as a TLS 1.3 server. This could result in a less preferred key exchange being used, contrary to expectations. This issue only affected Ubuntu 25.10. (CVE-2026-2673) Igor Morgenstern discovered that OpenSSL incorrectly handled certain memory operations when used as a DANE client. A remote attacker could use this issue to cause OpenSSL to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2026-28387) Igor Morgenstern discovered that OpenSSL incorrectly handled certain memory operations when processing a delta CRL. A remote attacker could possibly use this issue to cause OpenSSL to crash, resulting in a denial of service. (CVE-2026-28388) Nathan Sportsman, Daniel Rhea, and Jaeho Nam discovered that OpenSSL incorrectly handled certain memory operations when processing a crafted CMS EnvelopedData message with KeyAgreeRecipientInfo. A remote attacker could possibly use this issue to cause OpenSSL to crash, resulting in a denial of service. (CVE-2026-28389) Muhammad Daffa, Joshua Rogers, and Chanho Kim discovered that OpenSSL incorrectly handled processing of a crafted CMS EnvelopedData message with KeyTransportRecipientInfo. A remote attacker could possibly use this issue to cause OpenSSL to crash, resulting in a denial of service. (CVE-2026-28390) Quoc Tran discovered that OpenSSL incorrectly handled hexadecimal conversion on 32-bit platforms. A remote attacker could use this issue to cause OpenSSL to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2026-31789) Simo Sorce discovered that OpenSSL incorrectly handled failures in RSA KEM RSASVE Encapsulation. A remote attacker could possibly use this issue to obtain sensitive information. (CVE-2026-31790)