id: PYSEC-2026-2533
published: "2026-07-13T14:36:47.380994Z"
modified: "2026-07-13T16:04:22.882070Z"
aliases:
- CVE-2026-34052
- GHSA-8mxq-7xr7-2fxj
summary: "LTI JupyterHub Authenticator: Unbounded Memory Growth via Nonce Storage (Denial of Service)"
details: "## 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"
affected:
- package:
    name: jupyterhub-ltiauthenticator
    ecosystem: PyPI
    purl: pkg:pypi/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
references:
- type: WEB
  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
- type: WEB
  url: https://github.com/jupyterhub/ltiauthenticator/releases/tag/1.6.3
- type: PACKAGE
  url: https://pypi.org/project/jupyterhub-ltiauthenticator
- type: ADVISORY
  url: https://github.com/advisories/GHSA-8mxq-7xr7-2fxj
severity:
- type: CVSS_V3
  score: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H