CVE-2026-42504
Quadratic complexity in WordDecoder.DecodeHeader in mime
HIGH
7.5
CVSS Score
Published: June 2, 2026 at 10:01 PM UTC
Updated: October 31, 2026 at 10:22 AM UTC
1 product affected across 1 vendorMime
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Severity
HIGH7.5
Exploit prediction
EPSS 0.6%
SSVC
No known exploit
Description
Decoding a maliciously-crafted MIME header containing many invalid encoded-words can consume excessive CPU.
Affected
Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.
Affected range stops below 1.25.11, so it looks safe — our inference, not a vendor statement
Affected range stops below 1.26.4, so it looks safe — our inference, not a vendor statement
Remediation
No guide yetNo remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.
References (4)
Source: cverecord
https://go.dev/issue/79217Source: cverecord
https://go.dev/cl/774481Source: cverecord
https://groups.google.com/g/golang-announce/c/tKs3rmcBcKwSource: cverecord
https://pkg.go.dev/vuln/GO-2026-5038SSVC — Action Prioritization
SSVCNo known exploitAutomatablePartial impact
SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.
CVSS
7.5HIGH134c704f-9b21-4f2e-91b3-4a467353bcc0
- Attack Vector
- NETWORK
- Complexity
- LOW
- Privileges
- NONE
- User Interaction
- NONE
- Scope
- UNCHANGED
- Confidentiality
- NONE
- Integrity
- NONE
- Availability
- HIGH
Vector?
Quick Info
StatusAWAITING ANALYSIS
CWE
CWE-407
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