What is the CVSS score of CVE-2021-3626?

CVE-2021-3626 has a CVSS 3.1 base score of 8.8 (High). CVSS vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H. EPSS exploitation probability: 0.2%.

Is there a patch available for CVE-2021-3626?

Yes, a patch is available for CVE-2021-3626. Update the affected software to the latest version immediately.

Multipass CVE-2021-3626

HIGH

External Control of File Name or Path (CWE-73)

2021-10-01 security@ubuntu.com

Privilege Escalation Microsoft Canonical Multipass

8.8

CVSS 3.1 · NVD

View

Vulnerability Assessment

Weakness	CWE CWE-73 OWASP Top 10:2025 A06:2025 - Insecure Design ASVS 5.0 V5 - File Handling File name/path control
Impact	CVSS score of 8.8 (HIGH). Attack characteristics: local attack vector, low complexity, low privileges required, no user interaction not required.
Exploit ScenarioDerived	Successful exploitation could compromise the high-severity affected system.

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

Patch available 0.2% exploitation probability (EPSS)

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AnalysisAI

The Windows version of Multipass before 1.7.0 allowed any local process to connect to the localhost TCP control socket to perform mounts from the operating system to a guest, allowing for privilege. Rated high severity (CVSS 8.8), this vulnerability is low attack complexity.

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

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 under CWE-73. The Windows version of Multipass before 1.7.0 allowed any local process to connect to the localhost TCP control socket to perform mounts from the operating system to a guest, allowing for privilege escalation. Affected products include: Canonical Multipass. Version information: before 1.7.0.

Severity by source

NVD PRIMARY 8.8 HIGH

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Changed

Confidentiality

High

Integrity

High

Availability

High

DescriptionNVD

Threat Intelligence Overview

EPSS Score

0.2%

Top 85% 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 0.2%

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: +44

PoC: 0

Weaponized: 0

Threat intel: 0

Gov advisory: 0

Attack Technique

Privilege Escalation HIGH

Privilege escalation occurs when an attacker leverages flaws in access control mechanisms to gain permissions beyond what they were originally granted.