{"id":"CVE-2026-34052","aliases":["GHSA-8mxq-7xr7-2fxj","PYSEC-2026-2533"],"url":"https://o3.security/vulnerability/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.","published":"2026-04-03T22:04:10.519Z","modified":"2026-08-12T03:51:31.510384035Z","cvss":{"score":5.9,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"jupyterhub-ltiauthenticator","fixedVersion":"1.6.3"}],"fix":null,"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"},{"type":"PACKAGE","url":"https://github.com/jupyterhub/ltiauthenticator"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:31.510384035Z"}}