CVE-2026-42504
Quadratic complexity in WordDecoder.DecodeHeader in mime
Description
Decoding a maliciously-crafted MIME header containing many invalid encoded-words can consume excessive CPU.
INFO
Published Date :
June 2, 2026, 11:16 p.m.
Last Modified :
June 4, 2026, 4:15 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
Solution
- Update email processing software to the latest version.
- Implement strict validation for MIME header encoding.
- Monitor system resource utilization.
Public PoC/Exploit Available at Github
CVE-2026-42504 has a 5 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-42504.
| URL | Resource |
|---|---|
| https://go.dev/cl/774481 | |
| https://go.dev/issue/79217 | |
| https://groups.google.com/g/golang-announce/c/tKs3rmcBcKw | |
| https://pkg.go.dev/vuln/GO-2026-5038 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-42504 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-42504
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
grid-gym is an open-source platform for deterministic simulation and validation of smart grid and energy management systems. It supports replay simulations, fault injection, multi-agent control, and Modbus, MQTT, and real-time telemetry for research, development, and integration testing.
ems energy-management simulation smart-grid battery-storage bess fault-injection microgrid multi-agent-systems power-systems renewable-energy digital-twin docker modbus mqtt openapi replay-testing
Dockerfile Makefile Python Mako CSS HTML
Bridge between messaging platforms and AI coding agents — manage AI coding sessions from your phone
Makefile Go Shell HTML JavaScript CSS C Dockerfile Go Template Python
None
Dockerfile
Caddy Proxy Manager - Lightweight web UI for managing Caddy reverse proxy
Dockerfile Makefile Go HTML CSS JavaScript
None
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-42504 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-42504 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 03, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-407 -
New CVE Received by [email protected]
Jun. 02, 2026
Action Type Old Value New Value Added Description Decoding a maliciously-crafted MIME header containing many invalid encoded-words can consume excessive CPU. Added Reference https://go.dev/cl/774481 Added Reference https://go.dev/issue/79217 Added Reference https://groups.google.com/g/golang-announce/c/tKs3rmcBcKw Added Reference https://pkg.go.dev/vuln/GO-2026-5038