CVE-2026-34052 json
LTI JupyterHub Authenticator: Unbounded Memory Growth via Nonce Storage (Denial of Service)
published 7mo ago modified last mo. also EUVD-2026-18893 , GHSA-8mxq-7xr7-2fxj , PYSEC-2026-2533
- cvss
- 5.9
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 27%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- pypi jupyterhub-ltiauthenticator 1.6.3
- jupyter lti_jupyterhub_authenticator 1.6.3
Is CVE-2026-34052 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 7mo ago
Exploit prediction
0.34% chance of exploitation in the next 30 days, higher than 27% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 5.9 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H |
| GitHub | 3.1 | 5.9 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H |
| OSV | 3.1 | 5.9 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| pypi | jupyterhub-ltiauthenticator | <1.6.3 |
1.6.3 |
Affected products
- jupyterhub ltiauthenticator
Classification
References
-
github.com
/jupyterhub/ltiauthenticator/security/advisories/GHSA-8mxq-7xr7-2fxj
web, vendor-advisory
-
github.com
/jupyterhub/ltiauthenticator/releases/tag/1.6.3
web, product
-
nvd.nist.gov
/vuln/detail/CVE-2026-34052
advisory
-
github.com
/jupyterhub/ltiauthenticator
package
-
pypi.org
/project/jupyterhub-ltiauthenticator
package
-
github.com
/advisories/GHSA-8mxq-7xr7-2fxj
advisory
Sources
- CVE List CVE-2026-34052
- GitHub Advisory GHSA-8mxq-7xr7-2fxj
- NVD CVE-2026-34052
- OSV PYSEC-2026-2533
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.