USN-8447-2: LXD vulnerabilities

USN-8447-2: LXD vulnerabilities

https://ubuntu.com/security/notices/rss.xml / Thu, 06/18/2026 - 23:45
USN-8447-1 fixed vulnerabilities in Go Cryptography. This update provides the corresponding updates for Go Cryptography code embedded in LXD for CVE-2026-39830, CVE-2026-39833, CVE-2026-39834, and CVE-2026-42508. Original advisory details: It was discovered that Go Cryptography did not properly handle SSH global request responses. A remote attacker could possibly use this issue to cause a denial of service. (CVE-2026-39830) It was discovered that Go Cryptography did not properly verify user presence when using FIDO/U2F security keys. An attacker could possibly use this issue to bypass user presence verification for hardware security keys. This issue only affected Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 26.04 LTS. (CVE-2026-39831) It was discovered that Go Cryptography did not properly serialize SSH agent key constraint extensions. An attacker could possibly use this issue to bypass intended key usage restrictions. This issue only affected Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 26.04 LTS. (CVE-2026-39832) It was discovered that Go Cryptography did not properly enforce the confirm-before-use constraint in the SSH agent keyring. An attacker could possibly use this issue to use SSH keys without the required user confirmation. (CVE-2026-39833) It was discovered that Go Cryptography had an integer overflow when handling large SSH channel writes. A remote attacker could possibly use this issue to cause a denial of service. (CVE-2026-39834) It was discovered that Go Cryptography did not properly check certificate authority key revocation. An attacker could possibly use this issue to bypass certificate authority revocation checks. This issue only affected Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 26.04 LTS. (CVE-2026-42508) It was discovered that Go Cryptography did not properly enforce the source- address critical option for all SSH server callback types. An attacker could possibly use this issue to bypass source address authorization restrictions. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-46595)

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Kenya Education Network CERT(KENET-CERT) is a Cybersecurity Emergency Response Team and Co-ordination Center operated by the National Research and Education Network of Kenya. KENET-CERT coordination center promotes awareness on cybersecurity incidences as well as coordinates and assists member institutions in responding effectively to cyber security threats and incidences. KENET-CERT works closely with Kenya's National CIRT coordination center (CIRT/CC) as a sector CIRT for the academic institutions. KENET promotes use of ICT in Teaching, Learning and Research in Higher Education Institutions in Kenya. KENET aims to interconnect all the Universities, Tertiary and Research Institutions in Kenya by setting up a cost effective and sustainable private network with high speed access to the global Internet. KENET also facilitates electronic communication among students and faculties in member institutions, share learning and teaching resources by collaboration in Research and Development of Educational content.