CVE-2026-33943

High

fixedPATCH AVAILABLENot Available

Security vulnerability in happy-dom

Description

Happy DOM ECMAScriptModuleCompiler: unsanitized export names are interpolated as executable code

Happy DOM ECMAScriptModuleCompiler: unsanitized export names are interpolated as executable code This vulnerability involves weaknesses in

Impact Assessment

This high-severity vulnerability could allow attackers to gain unauthorized access, execute arbitrary code, or compromise data integrity. Prompt remediation is strongly recommended.

Attack Characteristics

Attack Vector

NETWORK

Complexity

LOW

Privileges Required

NONE

User Interaction

REQUIRED

CVSS v3.1 Score

8.8

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.97%

Probability of exploitation in the next 30 days · more likely than 61.2% of all CVEs.

Quick Facts

PublishedMar 26, 2026

Last ModifiedMar 30, 2026

Discovered ByIndependent Security Researcher

Statusfixed

Weakness Types

CWE-94

Unknown CWE

This vulnerability is associated with CWE-94. This type of weakness can lead to security issues if not properly addressed.

CWE-917

Unknown CWE

This vulnerability is associated with CWE-917. This type of weakness can lead to security issues if not properly addressed.

Attack Metrics

CVSS v3.1 Metrics Breakdown

attack Vector

NETWORK

attack Complexity

LOW

privileges Required

NONE

user Interaction

REQUIRED

scope

Unchanged

confidentiality Impact

High

integrity Impact

High

availability Impact

High

Remediation Guide

How to Fix This Vulnerability

Remediation Steps

1Upgrade the package to version 20.8.8 or later
2Review and audit affected systems for potential exploitation
3Implement additional security controls if immediate patching is not possible
4Monitor for suspicious activity related to this vulnerability

Mitigation Strategies

Immediate Patching

High

Apply security patches to version 20.8.8 immediately

Network Segmentation

High

Isolate affected systems from untrusted networks until patching is complete

Monitoring and Detection

Medium

Implement enhanced monitoring for exploitation attempts and unusual behavior

Event History

Vulnerability Timeline

Vulnerability published

2026-03-26T22:22:20Z

published

Patches released: 20.8.8

2026-03-26T22:22:20Z

patched

▪ Common questions

How severe is CVE-2026-33943?

CVE-2026-33943 is rated HIGH with a CVSS score of 8.8 (attack vector: NETWORK).

How do I fix CVE-2026-33943?

Upgrade the affected package to 20.8.8.

What kind of weakness is CVE-2026-33943?

CVE-2026-33943 is classified as CWE-94 — Security vulnerability in happy-dom.

Back to All Vulnerabilities

CVE-2026-33943

High

fixedPATCH AVAILABLENot Available

Security vulnerability in happy-dom

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Description

Happy DOM ECMAScriptModuleCompiler: unsanitized export names are interpolated as executable code

Happy DOM ECMAScriptModuleCompiler: unsanitized export names are interpolated as executable code This vulnerability involves weaknesses in

Impact Assessment

This high-severity vulnerability could allow attackers to gain unauthorized access, execute arbitrary code, or compromise data integrity. Prompt remediation is strongly recommended.

Attack Characteristics

Attack Vector

NETWORK

Complexity

LOW

Privileges Required

NONE

User Interaction

REQUIRED

CVSS v3.1 Score

8.8

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.97%

Probability of exploitation in the next 30 days · more likely than 61.2% of all CVEs.

Quick Facts

PublishedMar 26, 2026

Last ModifiedMar 30, 2026

Discovered ByIndependent Security Researcher

Statusfixed

Weakness Types

CWE-94

Unknown CWE

This vulnerability is associated with CWE-94. This type of weakness can lead to security issues if not properly addressed.

CWE-917

Unknown CWE

This vulnerability is associated with CWE-917. This type of weakness can lead to security issues if not properly addressed.

Attack Metrics

CVSS v3.1 Metrics Breakdown

attack Vector

NETWORK

attack Complexity

LOW

privileges Required

NONE

user Interaction

REQUIRED

scope

Unchanged

confidentiality Impact

High

integrity Impact

High

availability Impact

High

Remediation Guide

How to Fix This Vulnerability

Remediation Steps

1Upgrade the package to version 20.8.8 or later
2Review and audit affected systems for potential exploitation
3Implement additional security controls if immediate patching is not possible
4Monitor for suspicious activity related to this vulnerability

Mitigation Strategies

Immediate Patching

High

Apply security patches to version 20.8.8 immediately

Network Segmentation

High

Isolate affected systems from untrusted networks until patching is complete

Monitoring and Detection

Medium

Implement enhanced monitoring for exploitation attempts and unusual behavior

Event History

Vulnerability Timeline

Vulnerability published

2026-03-26T22:22:20Z

published

Patches released: 20.8.8

2026-03-26T22:22:20Z

patched

▪ Common questions

How severe is CVE-2026-33943?

CVE-2026-33943 is rated HIGH with a CVSS score of 8.8 (attack vector: NETWORK).

How do I fix CVE-2026-33943?

Upgrade the affected package to 20.8.8.

What kind of weakness is CVE-2026-33943?

CVE-2026-33943 is classified as CWE-94 — Security vulnerability in happy-dom.

Back to All Vulnerabilities