{"id":"CVE-2026-34052","aliases":["EUVD-2026-18893","GHSA-8mxq-7xr7-2fxj","PYSEC-2026-2533"],"status":"published","title":"LTI JupyterHub Authenticator: Unbounded Memory Growth via Nonce Storage (Denial of Service)","description":"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.","severity":{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00342,"percentile":0.27859,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-401","CWE-770"],"published":"2026-04-03T21:42:35Z","modified":"2026-10-28T02:31:14Z","fixes":[{"ecosystem":"PyPI","package":"jupyterhub-ltiauthenticator","fixed_in":["1.6.3"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"PyPI","package":"jupyterhub-ltiauthenticator","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"1.6.2"},{"fixed":"1.6.3"}]}]},{"source":"osv","ecosystem":"PyPI","package":"jupyterhub-ltiauthenticator","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.6.3"}]}],"versions":["0.1","0.2","0.3","0.4.0","1.0.0","1.1.0","1.2.0","1.3.0","1.4.0","1.5.0","1.5.1","1.6.0","1.6.1","1.6.2"]},{"source":"osv","ecosystem":"PyPI","package":"jupyterhub-ltiauthenticator","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.6.3"}]}],"versions":["0.1","0.2","0.3","0.4.0","1.0.0","1.1.0","1.2.0","1.3.0","1.4.0","1.5.0","1.5.1","1.6.0","1.6.1","1.6.2"]}],"products":[{"vendor":"jupyter","product":"lti_jupyterhub_authenticator"},{"vendor":"jupyterhub","product":"ltiauthenticator"}],"references":[{"url":"https://github.com/jupyterhub/ltiauthenticator/security/advisories/GHSA-8mxq-7xr7-2fxj","tags":["x_refsource_CONFIRM","Vendor Advisory","advisory","web"]},{"url":"https://github.com/jupyterhub/ltiauthenticator/releases/tag/1.6.3","tags":["x_refsource_MISC","Product","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-34052","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-8mxq-7xr7-2fxj","tags":["advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34052.json","tags":["advisory"]},{"url":"https://github.com/jupyterhub/ltiauthenticator","tags":["package"]},{"url":"https://pypi.org/project/jupyterhub-ltiauthenticator","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-34052","title":"LTI JupyterHub Authenticator: Unbounded Memory Growth via Nonce Storage (Denial of Service)","description":"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.","status":"published","published":"2026-04-03T22:04:10.519Z","modified":"2026-04-06T18:59:04.966Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"cna"}],"cwes":["CWE-401","CWE-770"],"updated_at":"2026-11-02T14:20:14.302133Z"}],"euvd":[{"id":"EUVD-2026-18893","description":"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.","status":"published","published":"2026-04-03T22:04:10Z","modified":"2026-04-06T18:59:04Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-02T19:25:15.380284Z"}],"ghsa":[{"id":"GHSA-8mxq-7xr7-2fxj","title":"LTI JupyterHub Authenticator: Unbounded Memory Growth via Nonce Storage (Denial of Service)","description":"## Summary\n\nThe 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.\n\n## Patches\n\n- upgrade jupyterhub-litauthenticator to 1.6.3","status":"published","published":"2026-04-03T21:42:35Z","modified":"2026-04-06T23:10:02Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"cwes":["CWE-401","CWE-770"],"updated_at":"2026-11-02T14:39:50.076383Z"}],"nvd":[{"id":"CVE-2026-34052","description":"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.","status":"published","published":"2026-04-03T23:17:03.777Z","modified":"2026-07-24T22:10:00.14Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"secondary"}],"cwes":["CWE-401","CWE-770"],"updated_at":"2026-11-02T14:12:13.1424Z"}],"osv":[{"id":"CVE-2026-34052","title":"LTI JupyterHub Authenticator: Unbounded Memory Growth via Nonce Storage (Denial of Service)","description":"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.","status":"published","published":"2026-04-03T22:04:10.519Z","modified":"2026-10-28T02:31:14.434321827Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"cwes":["CWE-401","CWE-770"],"updated_at":"2026-11-02T15:45:02.247031Z"},{"id":"GHSA-8mxq-7xr7-2fxj","title":"LTI JupyterHub Authenticator: Unbounded Memory Growth via Nonce Storage (Denial of Service)","description":"## Summary\n\nThe 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.\n\n## Patches\n\n- upgrade jupyterhub-litauthenticator to 1.6.3","status":"published","published":"2026-04-03T21:42:35Z","modified":"2026-09-10T03:51:01.296535015Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"cwes":["CWE-401","CWE-770"],"updated_at":"2026-11-02T15:46:42.437513Z"},{"id":"PYSEC-2026-2533","title":"LTI JupyterHub Authenticator: Unbounded Memory Growth via Nonce Storage (Denial of Service)","description":"## Summary\n\nThe 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.\n\n## Patches\n\n- upgrade jupyterhub-litauthenticator to 1.6.3","status":"published","published":"2026-07-13T14:36:47.380994Z","modified":"2026-07-13T16:31:58.992014411Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-02T15:52:55.961245Z"}]}}