CVE-2026-55517

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Source
https://cve.org/CVERecord?id=CVE-2026-55517
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-55517.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-55517
Aliases
Downstream
Published
2026-06-23T17:24:59.498Z
Modified
2026-08-12T03:51:49.134302786Z
Severity
  • 4.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L CVSS Calculator
Summary
Deno: Denial of service via non-ASCII bytes in WebSocket response headers
Details

Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.7.5, a Deno program that opens a client WebSocket connection could be crashed by the remote server. While handling the WebSocket handshake response, Deno parsed the Sec-WebSocket-Protocol and Sec-WebSocket-Extensions response headers in a way that assumed their bytes were always printable ASCII. A response header containing non-visible-ASCII bytes (0x80-0xFF) caused a panic that aborted the entire Deno process. This vulnerability is fixed in 2.7.5.

Database specific 
{
    "cwe_ids": [
        "CWE-248"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55517.json",
    "cna_assigner": "GitHub_M"
}
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
0238181e8a95be0885da93bbc99997988d07bff0
Database specific
Show details 
{
    "cpe": "cpe:2.3:a:deno:deno:*:*:*:*:*:*:*:*",
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "fixed": "2.7.5"
        }
    ],
    "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
v2.7.2
v2.7.3
v2.7.4

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-55517.json"