Security Digest · Vulnerability record
CVE-2023-25574: LTI JupyterHub Authenticator does not properly validate JWT Signature
jupyterhub-ltiauthenticator is a JupyterHub authenticator for learning tools interoperability (LTI).
CVSS 10.0 Critical EPSS 0.4% · p28
Should you act?
Critical and remotely reachable
No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.
- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.4%, percentile 28: FIRST’s model estimates a 0.4% chance of exploitation activity in the next 30 days, higher than 28% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes
jupyterhub-ltiauthenticator(PyPI) = 1.3.0, fixed in 1.4.0. Check your lockfile, including transitive dependencies.
What it is
jupyterhub-ltiauthenticator is a JupyterHub authenticator for learning tools interoperability (LTI). LTI13Authenticator that was introduced in jupyterhub-ltiauthenticator 1.3.0 wasn't validating JWT signatures. This is believed to allow the LTI13Authenticator to authorize a forged request. Only users that has configured a JupyterHub installation to use the authenticator class LTI13Authenticator are affected. jupyterhub-ltiauthenticator version 1.4.0 removes LTI13Authenticator to address the issue. No known workarounds are available.
From the GitHub advisory
Impact
Only users that has configured a JupyterHub installation to use the authenticator class LTI13Authenticator are influenced.
LTI13Authenticator that was introduced in jupyterhub-ltiauthenticator 1.3.0 wasn't validating JWT signatures. This is believed to allow the LTI13Authenticator to authorize a forged request granting access to existing and new user identities.
Patches
None.
Weakness type: CWE-347.
Product: jupyterhub-ltiauthenticator (PyPI) · Assigned by: GitHub_M · Published: 2025-02-25
Affected and fixed versions
| Ecosystem | Package | Vulnerable | First fixed |
|---|---|---|---|
| PyPI | jupyterhub-ltiauthenticator | = 1.3.0 | 1.4.0 |
| Vendor | Product | Affected versions (per CVE record) |
|---|---|---|
| jupyterhub | ltiauthenticator | = 1.3.0 |
Severity scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_M | 3.1 | 10 Critical | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |
| GitHub | 3.1 | 10.0 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |
- Attack vector: network (remotely reachable)
- Attack complexity: low
- Privileges required: none (no login)
- User interaction: none
- Scope: changed (can affect other components)
CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.
Exploitation and urgency
- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none, automatable yes, technical impact total.
- FIRST EPSS (model of 2026-10-21): 0.36% probability of exploitation activity in the next 30 days; percentile 28.
Timeline
- — CVE record last updated
- — CVE record published by GitHub_M
- — GitHub-reviewed advisory GHSA-mcgx-2gcr-p3hp published (critical)
Sources and references
Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.
Vulnerability records
- GitHub Advisory GHSA-mcgx-2gcr-p3hp github.com
- CVE.org record CVE-2023-25574 cve.org
- NVD entry CVE-2023-25574 nvd.nist.gov
Other references from the CVE record and advisory
- github.com github.com
- github.com github.com
- github.com github.com
- github.com github.com