CVE-2026-49859

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Source
https://cve.org/CVERecord?id=CVE-2026-49859
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-49859.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-49859
Aliases
Published
2026-06-23T17:14:16.888Z
Modified
2026-07-08T08:13:41.104828750Z
Severity
  • 5.2 (Medium) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N CVSS Calculator
Summary
Deno: `fetch()` API sandbox bypass via missing DNS resolution check
Details

Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.8.1, when fetch() was called, Deno checked the destination hostname against --deny-net rules but did not re-check the IP addresses that hostname resolved to. An attacker-controlled script could use a specially crafted domain name that passes the hostname check yet resolves to a denied IP, bypassing the network restriction entirely. This vulnerability is fixed in 2.8.1.

Database specific 
{
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-693",
        "CWE-918"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/49xxx/CVE-2026-49859.json"
}
References

Affected packages

Git / github.com/denoland/deno

Affected ranges

Type
GIT
Repo
https://github.com/denoland/deno
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
3e2030bc01776ce6b4ca355b1e78c4cb98c82dca
Database specific 
{
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "fixed": "2.8.1"
        }
    ],
    "cpe": "cpe:2.3:a:deno:deno:*:*:*:*:*:*:*:*",
    "source": [
        "AFFECTED_FIELD",
        "CPE_RANGE"
    ]
}

Affected versions

std/0.*
std/0.34.0
std/0.35.0
std/0.36.0
std/0.37.0
std/0.38.0
std/0.39.0
std/0.40.0
std/0.41.0
std/0.42.0
std/0.50.0
std/0.51.0
std/0.52.0
std/0.53.0
std/0.54.0
std/0.55.0
std/0.56.0
std/0.57.0
std/0.58.0
std/0.59.0
std/0.60.0
std/0.61.0
std/0.62.0
std/0.63.0
std/0.64.0
std/0.65.0
std/0.66.0
std/0.67.0
std/0.68.0
std/0.69.0
std/0.70.0
std/0.71.0
std/0.72.0
std/0.73.0
std/0.74.0
std/0.75.0
std/0.76.0
std/0.77.0
std/0.78.0
std/0.79.0
std/0.80.0
std/0.81.0
std/0.82.0
std/0.83.0
std/0.84.0
std/0.85.0
v0.*
v0.0.1
v0.0.3
v0.1.0
v0.1.1
v0.1.10
v0.1.11
v0.1.12
v0.1.2
v0.1.3
v0.1.4
v0.1.5
v0.1.6
v0.1.7
v0.1.8
v0.1.9
v0.10.0
v0.11.0
v0.12.0
v0.13.0
v0.14.0
v0.15.0
v0.16.0
v0.17.0
v0.18.0
v0.19.0
v0.2.0
v0.2.1
v0.2.10
v0.2.11
v0.2.2
v0.2.3
v0.2.4
v0.2.5
v0.2.6
v0.2.7
v0.2.8
v0.2.9
v0.20.0
v0.21.0
v0.22.0
v0.23.0
v0.24.0
v0.25.0
v0.26.0
v0.27.0
v0.28.0
v0.28.1
v0.29.0
v0.3.0
v0.3.1
v0.3.10
v0.3.11
v0.3.2
v0.3.3
v0.3.4
v0.3.5
v0.3.6
v0.3.7
v0.3.8
v0.3.9
v0.30.0
v0.30.1
v0.31.0
v0.32.0
v0.33.0
v0.34.0
v0.35.0
v0.36.0
v0.37.0
v0.37.1
v0.38.0
v0.39.0
v0.4.0
v0.40.0
v0.41.0
v0.42.0
v0.5.0
v0.6.0
v0.7.0
v0.8.0
v0.9.0
v1.*
v1.0.0
v1.0.0-rc1
v1.0.0-rc2
v1.0.0-rc3
v1.0.1
v1.0.2
v1.0.3
v1.0.4
v1.0.5
v1.1.0
v1.1.1
v1.1.2
v1.1.3
v1.10.0
v1.10.1
v1.11.0
v1.11.1
v1.11.2
v1.12.0
v1.12.1
v1.12.2
v1.13.0
v1.13.1
v1.13.2
v1.14.0
v1.14.1
v1.14.2
v1.15.0
v1.15.1
v1.15.2
v1.15.3
v1.16.0
v1.16.1
v1.16.2
v1.17.0
v1.18.0
v1.19.0
v1.2.0
v1.2.1
v1.2.2
v1.2.3
v1.20.0
v1.20.1
v1.21.0
v1.22.0
v1.23.0
v1.24.0
v1.25.0
v1.26.0
v1.27.0
v1.28.0
v1.29.0
v1.3.0
v1.3.1
v1.3.2
v1.3.3
v1.30.0
v1.31.0
v1.32.0
v1.33.0
v1.34.0
v1.35.0
v1.36.0
v1.37.0
v1.38.0
v1.39.0
v1.4.0
v1.4.1
v1.4.2
v1.4.3
v1.4.4
v1.4.5
v1.4.6
v1.40.0
v1.41.0
v1.42.0
v1.43.0
v1.43.1
v1.44.0
v1.45.0
v1.46.0
v1.5.0
v1.5.1
v1.5.2
v1.5.3
v1.5.4
v1.6.0
v1.6.1
v1.6.2
v1.6.3
v1.7.0
v1.7.1
v1.7.2
v1.7.3
v1.7.4
v1.8.0
v1.8.1
v1.8.2
v1.9.0
v1.9.1
v1.9.2
v2.*
v2.0.0
v2.1.0
v2.2.0
v2.3.0
v2.3.1
v2.3.2
v2.3.3
v2.3.4
v2.3.5
v2.3.6
v2.3.7
v2.4.0
v2.4.1
v2.4.2
v2.4.3
v2.4.4
v2.4.5
v2.5.0
v2.5.1
v2.5.2
v2.5.3
v2.5.4
v2.5.5
v2.5.6
v2.6.0
v2.6.10
v2.6.2
v2.6.3
v2.6.4
v2.6.5
v2.6.6
v2.6.7
v2.6.8
v2.6.9
v2.7.0
v2.7.1
v2.7.10
v2.7.11
v2.7.12
v2.7.13
v2.7.14
v2.7.2
v2.7.3
v2.7.4
v2.7.5
v2.7.6
v2.7.7
v2.7.8
v2.7.9
v2.8.0

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-49859.json"