USN-8823-1: PyJWT vulnerabilities

USN-8823-1: PyJWT vulnerabilities

https://ubuntu.com/security/notices/rss.xml / Mon, 09/28/2026 - 10:49
It was discovered that PyJWT incorrectly handled certain URIs when using PyJWKClient. A remote attacker could possibly use this issue to perform server-side request forgery (SSRF) or expose sensitive local files. This issue only affected Ubuntu 22.04 LTS, Ubuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-48522) It was discovered that PyJWT incorrectly verified cryptographic signatures when decoding tokens with PyJWK keys. A remote attacker could possibly use this issue to bypass signature verification and forge valid JSON Web Tokens. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-48523) It was discovered that PyJWT incorrectly handled unknown key identifiers in PyJWKClient. A remote attacker could possibly use this issue to cause PyJWT to make excessive network requests, resulting in a denial of service. This issue only affected Ubuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-48524) It was discovered that PyJWT incorrectly handled payload decoding during detached JWS token verification. A remote attacker could possibly use this issue to cause PyJWT to consume excessive resources, resulting in a denial of service. This issue only affected Ubuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-48525) It was discovered that PyJWT incorrectly validated JSON Web Keys when decoding tokens with both HMAC and asymmetric algorithms enabled. A remote attacker could possibly use this issue to forge valid tokens, resulting in an authentication bypass. (CVE-2026-48526)

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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.