ESB-2026.5662

=========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2026.5662 USN-8280-2: Linux kernel (Azure)vulnerabilities 26 May 2026 =========================================================================== AUSCERT Security Bulletin Summary --------------------------------- Product: Linux kernel (Azure) Publisher: Ubuntu Operating System: Ubuntu Resolution: Patch/Upgrade CVE Names: CVE-2026-43078 CVE-2026-43077 CVE-2026-43033 CVE-2026-31533 CVE-2026-31504 CVE-2026-31431 Original Bulletin: https://ubuntu.com/security/notices/USN-8280-2 Comment: CVSS (Max): 9.8 CVE-2026-31533 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) CVSS Source: Ubuntu 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:H/A:H The following are listed in the CISA Known Exploited Vulnerabilities (KEV) Catalog: CISA KEV CVE(s): CVE-2026-31431 CISA KEV URL: https://www.cisa.gov/known-exploited-vulnerabilities-catalog EPSS (Max): 2.6% (85th) CVE-2026-31431 2026-05-25 - --------------------------BEGIN INCLUDED TEXT-------------------- USN-8280-2: Linux kernel (Azure)vulnerabilities Publication date 22 May 2026 Overview Several security issues were fixed in the Linux kernel. Releases 20.04 LTS 18.04 LTS --------------------------------------------------------------------------------- Open side navigation Packages o linux-azure - Linux kernel for Microsoft Azure Cloud systems o linux-azure-5.4 - Linux kernel for Microsoft Azure cloud systems o linux-azure-fips - Linux kernel for Microsoft Azure Cloud systems with FIPS Details It was discovered that the Linux kernel algif_aead module did not properly handle in-place cryptographic operations. This flaw is known as Copy Fail. A local attacker could use this to escalate privileges, or possibly escape a container. ( CVE-2026-31431 ) Several security issues were discovered in the Linux kernel. An attacker could possibly use these to compromise the system. This update corrects flaws in the following subsystems: o Cryptographic API; o Packet sockets; o TLS protocol Update instructions ATTENTION: Due to an unavoidable ABI change the kernel updates have been given a new version number, which requires you to recompile and reinstall all third party kernel modules you might have installed. Unless you manually uninstalled the standard kernel metapackages (e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual, linux-powerpc), a standard system upgrade will automatically perform this as well. The problem can be corrected by updating your system to the following package versions: Ubuntu Package Version Release linux-image-5.4.0-1163-azure - 5.4.0-1163.169 Ubuntu Pro Fix available with Ubuntu Pro . linux-image-5.4.0-1163-azure-fips - 5.4.0-1163.169+fips1 FIPS Updates FIPS-140 certified package with security fixes. Available with Ubuntu Pro. 20.04 LTS linux-image-azure-5.4 - 5.4.0.1163.155 Ubuntu Pro Fix available with focal Ubuntu Pro . linux-image-azure-fips - 5.4.0.1163.99 FIPS Updates FIPS-140 certified package with security fixes. Available with Ubuntu Pro. linux-image-azure-fips-5.4 - 5.4.0.1163.99 FIPS Updates FIPS-140 certified package with security fixes. Available with Ubuntu Pro. linux-image-azure-lts-20.04 - 5.4.0.1163.155 Ubuntu Pro Fix available with Ubuntu Pro . linux-image-5.4.0-1163-azure - 5.4.0-1163.169~18.04.1 Ubuntu Pro Fix available with Ubuntu Pro . 18.04 LTS linux-image-azure - 5.4.0.1163.169~18.04.1 Ubuntu Pro Fix available bionic with Ubuntu Pro . linux-image-azure-5.4 - 5.4.0.1163.169~18.04.1 Ubuntu Pro Fix available with Ubuntu Pro . --------------------------------------------------------------------------------- References o CVE-2026-43078 o CVE-2026-43077 o CVE-2026-43033 o CVE-2026-31533 o CVE-2026-31504 o CVE-2026-31431 Related notices o USN-8289-1 o USN-8281-1 o USN-8281-2 o USN-8280-1 o USN-8279-1 o USN-8279-2 o USN-8278-1 o USN-8277-1 o USN-8277-2 o USN-8226-1 o USN-8226-2 --------------------------------------------------------------------------------- - --------------------------END INCLUDED TEXT---------------------- You have received this e-mail bulletin as a result of your organisation's registration with AUSCERT. 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