CVE-2026-49859

High

fixedPATCH AVAILABLENot Available

Security vulnerability in deno

Description

Deno: fetch() API sandbox bypass via missing DNS resolution check

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.

CVSS v3.1 Score

7.5

EPSS — Exploit Prediction

0.14%

Probability of exploitation in the next 30 days · more likely than 3.0% of all CVEs.

Quick Facts

PublishedJun 16, 2026

Last ModifiedJun 16, 2026

Discovered ByIndependent Security Researcher

Statusfixed

Attack Metrics

CVSS v3.1 Metrics Breakdown

attack Vector

attack Complexity

privileges Required

user Interaction

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 2.8.1 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 2.8.1 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

2026-06-16T19:02:55Z

published

Patches released: 2.8.1

2026-06-16T19:02:55Z

patched

▪ Common questions

How severe is CVE-2026-49859?

CVE-2026-49859 is rated HIGH with a CVSS score of 7.5.

How do I fix CVE-2026-49859?

Upgrade the affected package to 2.8.1.

Back to All Vulnerabilities

CVE-2026-49859

High

fixedPATCH AVAILABLENot Available

Security vulnerability in deno

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Description

Deno: fetch() API sandbox bypass via missing DNS resolution check

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.

CVSS v3.1 Score

7.5

EPSS — Exploit Prediction

0.14%

Probability of exploitation in the next 30 days · more likely than 3.0% of all CVEs.

Quick Facts

PublishedJun 16, 2026

Last ModifiedJun 16, 2026

Discovered ByIndependent Security Researcher

Statusfixed

Attack Metrics

CVSS v3.1 Metrics Breakdown

attack Vector

attack Complexity

privileges Required

user Interaction

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 2.8.1 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 2.8.1 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

2026-06-16T19:02:55Z

published

Patches released: 2.8.1

2026-06-16T19:02:55Z

patched

▪ Common questions

How severe is CVE-2026-49859?

CVE-2026-49859 is rated HIGH with a CVSS score of 7.5.

How do I fix CVE-2026-49859?

Upgrade the affected package to 2.8.1.

Back to All Vulnerabilities