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USN-8916-1: PyJWT vulnerabilities

YuSung Han discovered that PyJWT did not properly validate certain JWK keys when performing HMAC verification. An attacker could possibly use this issue to forge authentication tokens. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-102266) Rohan Das discovered that PyJWT incorrectly handled redirects when fetching key sets. A remote attacker could possibly use this issue to cause PyJWT to disclose sensitive information. This issue only affected Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, Ubuntu 26.04 LTS. (CVE-2026-102267) It was discovered that PyJWT incorrectly recognized certain PEM representations. An attacker who knew the public key could possibly use this issue to forge authentication tokens. This issue only affected Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, Ubuntu 26.04 LTS. (CVE-2026-102268) Nuno Lopes discovered that PyJWT incorrectly handled DER public keys when performing HMAC verification. An attacker who knew the public key could possibly use this issue to forge authentication tokens. (CVE-2026-102271) It was discovered that PyJWT did not properly handle certain JWK keys prefixed with a byte-order mark. An attacker who knew the public key could possibly use this issue to forge authentication tokens. (CVE-2026-102272) Charles Vosburgh discovered that PyJWT incorrectly handled certain JWK containers when performing HMAC verification. An attacker who knew the public key could possibly use this issue to forge authentication tokens. (CVE-2026-102273)

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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.