Quadratic complexity in WordDecoder.DecodeHeader in mime_CVE-2026-42504

7.5 / 10

HIGH

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

Description

Decoding a maliciously-crafted MIME header containing many invalid encoded-words can consume excessive CPU.

Basic Information

ID CVE-2026-42504

Source Go

Published Jun 2, 2026 at 22:01

Modified Jun 3, 2026 at 14:06

Affected Product

Vendor Go standard library

Product mime

Affected Versions Go standard library mime 0
Go standard library mime 1.26.0-0

CWE Classification

CWE-407

References

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    "lastseen": "",
    "description": "Decoding a maliciously-crafted MIME header containing many invalid encoded-words can consume excessive CPU.",
    "published": "2026-06-02T22:01:37.219Z",
    "modified": "2026-06-03T14:06:13.623Z",
    "type": "cve",
    "title": "Quadratic complexity in WordDecoder.DecodeHeader in mime",
    "source": "Go",
    "references": "https://go.dev/issue/79217\nhttps://go.dev/cl/774481\nhttps://groups.google.com/g/golang-announce/c/tKs3rmcBcKw\nhttps://pkg.go.dev/vuln/GO-2026-5038",
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    "sourceData": "Go standard library mime 0\nGo standard library mime 1.26.0-0",
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    "cvss": {
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        "version": "3.1"
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    "href": "",
    "category_name": "CVE",
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    "product": "mime",
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