CVE-2026-49859Hinoki check available

Network sandbox bypass via unchecked resolved addresses

Published Jun 23, 2026 · Updated Jun 23, 2026

SSRF in Deno before 2.8.1 allows local users to reach network destinations blocked by --deny-net through a crafted DNS response. The fetch() path checked the requested hostname against deny rules but sent resolved IP addresses to the HTTP connector without rechecking them. Exploitation requires untrusted or third-party code to run with network access constrained by --deny-net; successful abuse reaches localhost or internal services that the policy was intended to isolate.

CVSS severity5.2
Medium
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

SSRF in Deno before 2.8.1 allows local users to reach network destinations blocked by --deny-net through a crafted DNS response. The fetch() path checked the requested hostname against deny rules but sent resolved IP addresses to the HTTP connector without rechecking them. Exploitation requires untrusted or third-party code to run with network access constrained by --deny-net; successful abuse reaches localhost or internal services that the policy was intended to isolate.

The record

CVE
CVE-2026-49859
Published
Jun 23, 2026
Updated
Jun 23, 2026
Vendor
Deno Land
Product
Deno
Classifications
CWE-918, CWE-693
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Jun 23, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 23, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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  1. Affected versionversion=< 2.8.1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

Deno Land · Denoversion=< 2.8.1

Published CVSS scores

5.2GitHub, Inc.CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-918Server-Side Request Forgery (SSRF)
CWE-693Protection Mechanism Failure

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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