---
title: "CVE-2023-25574: LTI JupyterHub Authenticator does not properly validate JWT Signature"
url: https://erroneo.us/security/cve/CVE-2023-25574/
description: "CVE-2023-25574 (jupyterhub-ltiauthenticator (PyPI)): jupyterhub-ltiauthenticator is a JupyterHub authenticator for learning tools interoperability (LTI).…"
type: vulnerability-record
section: "Security Digest"
date_published: 2025-02-25
date_modified: 2026-06-05
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2023-25574"
kev: false
cvss: 10
epss: 0.00355
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2023-25574: LTI JupyterHub Authenticator does not properly validate JWT Signature

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- 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.

## Affected packages

- PyPI `jupyterhub-ltiauthenticator` = 1.3.0 → fixed: 1.4.0

## Affected products (CVE record)

- jupyterhub ltiauthenticator: = 1.3.0

## Severity

- GitHub_M CVSS 3.1: 10 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H`
- GitHub CVSS 3.1: 10.0 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H`

## Exploitation

- 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.

## Sources

- [GitHub Advisory GHSA-mcgx-2gcr-p3hp](https://github.com/advisories/GHSA-mcgx-2gcr-p3hp)
- [CVE.org record CVE-2023-25574](https://www.cve.org/CVERecord?id=CVE-2023-25574)
- [NVD entry CVE-2023-25574](https://nvd.nist.gov/vuln/detail/CVE-2023-25574)
- [github.com](https://github.com/jupyterhub/ltiauthenticator/security/advisories/GHSA-mcgx-2gcr-p3hp)
- [github.com](https://github.com/jupyterhub/ltiauthenticator/blob/3feec2e81b9d3b0ad6b58ab4226af640833039f3/ltiauthenticator/lti13/validator.py#L122-L164)
- [github.com](https://github.com/jupyterhub/ltiauthenticator/blob/main/CHANGELOG.md#140---2023-03-01)
- [github.com](https://github.com/pypa/advisory-database/tree/main/vulns/jupyterhub-ltiauthenticator/PYSEC-2025-120.yaml)

---
Source page: https://erroneo.us/security/cve/CVE-2023-25574/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt