CVE-2026-42504

Quadratic complexity in WordDecoder.DecodeHeader in mime

Published Jun 2, 2026 CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed
Description
Decoding a maliciously-crafted MIME header containing many invalid encoded-words can consume excessive CPU.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Weaknesses CWE-407
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Golang
Golang mime
Vendors & Products Golang
Golang mime
Type Values Removed Values Added
Weaknesses CWE-442
Type Values Removed Values Added
Description Decoding a maliciously-crafted MIME header containing many invalid encoded-words can consume excessive CPU.
Title Quadratic complexity in WordDecoder.DecodeHeader in mime
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
Go
Published
Updated
Nov 13, 2026, 5:21 PM
Reserved
Apr 28, 2026, 12:21 AM
Status
Awaiting Analysis
Published
Jun 2, 2026, 11:16 PM
Modified
Jul 22, 2026, 7:10 PM