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USN-8910-1: libxml2 vulnerabilities

Yirou Yang discovered that libxml2 incorrectly handled certain XML catalogs. If a user or automated system was tricked into processing a specially crafted XML catalog, an attacker could possibly use this issue to cause libxml2 to crash, resulting in a denial of service. (CVE-2026-76781) It was discovered that libxml2 incorrectly handled certain large qualified names, leading to a heap-based buffer overflow. An attacker could possibly use this issue to cause libxml2 to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2026-86138) It was discovered that libxml2 incorrectly handled escaping certain large URI strings. An attacker could possibly use this issue to cause libxml2 to use excessive resources, leading to a denial of service. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-86139) Xudong Cao and Meng Xu discovered that libxml2 incorrectly handled certain large XPointer expressions, leading to a heap-based buffer overflow. An attacker could possibly use this issue to cause libxml2 to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2026-86142) Xudong Cao and Meng Xu discovered that libxml2 did not check for integer overflows before passing output lengths to write callbacks. An attacker could possibly use this issue to cause an application using libxml2 to crash, resulting in a denial of service. (CVE-2026-86143) It was discovered that libxml2 did not apply parser options, such as disabling network access, when processing XInclude directives under certain circumstances. An attacker could possibly use this issue to perform XML external entity injection or server-side request forgery attacks, or cause a denial of service. (CVE-2026-86144)

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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.