Resource Exhaustion in Go Programming Language by Google
CVE-2026-42504

7.5HIGH

Key Information:

Vendor

Go Standard Library

Status
Mime
Vendor
CVE Published:
2 June 2026

What is CVE-2026-42504?

This vulnerability arises when a maliciously-crafted MIME header includes numerous invalid encoded-words, leading to excessive CPU usage as the decoder processes these headers. Applications utilizing the Go programming language may experience performance degradation due to this flaw, affecting service availability and system responsiveness.

Affected Version(s)

mime 0 < 1.25.11

mime 1.26.0-0 < 1.26.4

References

https://go.dev/issue/79217
https://go.dev/cl/774481
https://groups.google.com/g/golang-announce/c/tKs3rmcBcKw

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

p4p3r (https://hackerone.com/p4p3r_hak)
.