{"id":"CVE-2026-34052","summary":"LTI JupyterHub Authenticator: Unbounded Memory Growth via Nonce Storage (Denial of Service)","details":"LTI JupyterHub Authenticator is a JupyterHub authenticator for LTI. Prior to version 1.6.3, the LTI 1.1 validator stores OAuth nonces in a class-level dictionary that grows without bounds. Nonces are added before signature validation, so an attacker with knowledge of a valid consumer key can send repeated requests with unique nonces to gradually exhaust server memory, causing a denial of service. This issue has been patched in version 1.6.3.","aliases":["GHSA-8mxq-7xr7-2fxj"],"modified":"2026-05-18T11:54:52.749033524Z","published":"2026-04-03T22:04:10.519Z","related":["CGA-cr29-6366-hc95"],"database_specific":{"cwe_ids":["CWE-401","CWE-770"],"cna_assigner":"GitHub_M","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34052.json"},"references":[{"type":"WEB","url":"https://github.com/jupyterhub/ltiauthenticator/releases/tag/1.6.3"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34052.json"},{"type":"ADVISORY","url":"https://github.com/jupyterhub/ltiauthenticator/security/advisories/GHSA-8mxq-7xr7-2fxj"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-34052"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/jupyterhub/ltiauthenticator","events":[{"introduced":"0"},{"fixed":"4fb95e2b72ec87c2000c5b6ea1968479c1a82382"}]}],"versions":["1.6.2","1.6.1","1.6.0","1.5.1","1.5.0","1.4.0","1.3.0","1.2.0","1.1.0","1.0.0","0.4.0","v0.3"],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-34052.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}