What is the CVSS score of CVE-2020-26261?

CVE-2020-26261 has a CVSS 3.1 base score of 7.9 (High). CVSS vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N. EPSS exploitation probability: 0.5%.

Is there a patch available for CVE-2020-26261?

Yes, a patch is available for CVE-2020-26261. Update the affected software to the latest version immediately.

Jupyterhub CVE-2020-26261

HIGH

Exposure of Resource to Wrong Sphere (CWE-668)

2020-12-09 security-advisories@github.com

Information Disclosure Jupyterhub Systemdspawner

7.9

CVSS 3.1 · NVD

View

Vulnerability Assessment

Weakness	CWE CWE-668 OWASP Top 10:2025 A01:2025 - Broken Access Control ASVS 5.0 V8 - Authorization Resource sphere isolation MITRE ATT&CK 1 technique across 1 tactic: Collection The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. Sign in to read
Impact	CVSS score of 7.9 (HIGH). Attack characteristics: local attack vector, low complexity, low privileges required, user interaction required.
Exploit ScenarioDerived	A local attacker with access to the system could access resources from an unintended security context.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).

Patch available 0.5% exploitation probability (EPSS)

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AnalysisAI

jupyterhub-systemdspawner enables JupyterHub to spawn single-user notebook servers using systemd. Rated high severity (CVSS 7.9), this vulnerability is low attack complexity. This Exposure of Resource to Wrong Sphere vulnerability could allow attackers to access resources from an unintended security context.

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Implement proper access controls, validate resource access permissions, use security boundaries.

Affected Packages

pypi jupyterhub-systemdspawner fix: 0.15.0

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in pypi

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

This vulnerability is classified as Exposure of Resource to Wrong Sphere (CWE-668), which allows attackers to access resources from an unintended security context. jupyterhub-systemdspawner enables JupyterHub to spawn single-user notebook servers using systemd. In jupyterhub-systemdspawner before version 0.15 user API tokens issued to single-user servers are specified in the environment of systemd units. These tokens are incorrectly accessible to all users. In particular, the-littlest-jupyterhub is affected, which uses systemdspawner by default. This is patched in jupyterhub-systemdspawner v0.15 Affected products include: Jupyterhub Systemdspawner. Version information: version 0.15.

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

NVD PRIMARY 7.9 HIGH

AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

Required

Scope

Changed

Confidentiality

High

Integrity

High

Availability

None

DescriptionNVD

jupyterhub-systemdspawner enables JupyterHub to spawn single-user notebook servers using systemd. In jupyterhub-systemdspawner before version 0.15 user API tokens issued to single-user servers are specified in the environment of systemd units. These tokens are incorrectly accessible to all users. In particular, the-littlest-jupyterhub is affected, which uses systemdspawner by default. This is patched in jupyterhub-systemdspawner v0.15

Threat Intelligence Overview

EPSS Score

0.5%

Top 62% exploitable

Data Quality

3 sources

Confidence: Low

NVD

CVE.org

EPSS

GitHub

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity HIGH

CISA KEV No

Public POC No

EPSS 0.5%

Patch available Yes

Active threat No

Deciding rule

HIGH severity (CVSS 7.0-8.9)

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived

Defer

Exploitation· derived

None

System Exposure· derived

Small

Automatable· derived

Human Impact· derived

Medium

Priority Score

Low Medium High Critical

KEV: 0

EPSS: 0

CVSS: +40

PoC: 0

Weaponized: 0

Threat intel: 0

Gov advisory: 0

Attack Technique

Information Disclosure MEDIUM

Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.