ESB-2026.3424

=========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2026.3424 USN-8155-1: OpenSSL vulnerabilities 9 April 2026 =========================================================================== AUSCERT Security Bulletin Summary --------------------------------- Product: OpenSSL Publisher: Ubuntu Operating System: Ubuntu Resolution: Patch/Upgrade CVE Names: CVE-2026-2673 CVE-2026-28387 CVE-2026-28388 CVE-2026-28389 CVE-2026-28390 CVE-2026-31789 CVE-2026-31790 Original Bulletin: https://ubuntu.com/security/notices/USN-8155-1 Comment: CVSS (Max): 7.5* CVE-2026-31790 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N) CVSS Source: Ubuntu, [CISA-ADP], SUSE Calculator: https://www.first.org/cvss/calculator/3.1#CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N * Not all CVSS available when published EPSS (Max): 0.0% (13th) CVE-2026-2673 2026-04-08 - --------------------------BEGIN INCLUDED TEXT-------------------- USN-8155-1: OpenSSL vulnerabilities Publication date 8 April 2026 Overview Several security issues were fixed in OpenSSL. Releases 25.10 24.04 LTS 22.04 LTS --------------------------------------------------------------------------------- Open side navigation Packages o openssl - Secure Socket Layer (SSL) cryptographic library and tools Details 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 ) --------------------------------------------------------------------------------- Update instructions The problem can be corrected by updating your system to the following package versions: Ubuntu Release Package Version 25.10 questing libssl3t64 - 3.5.3-1ubuntu3.3 openssl - 3.5.3-1ubuntu3.3 24.04 LTS noble libssl3t64 - 3.0.13-0ubuntu3.9 openssl - 3.0.13-0ubuntu3.9 22.04 LTS jammy libssl3 - 3.0.2-0ubuntu1.23 openssl - 3.0.2-0ubuntu1.23 --------------------------------------------------------------------------------- References o CVE-2026-31790 o CVE-2026-31789 o CVE-2026-28390 o CVE-2026-28389 o CVE-2026-28388 o CVE-2026-28387 o CVE-2026-2673 - --------------------------END INCLUDED TEXT---------------------- You have received this e-mail bulletin as a result of your organisation's registration with AUSCERT. 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