What is CVE-2026-42504?

CVE-2026-42504 is a security advisory published by Microsoft Security Response Center (MSRC) with High severity. Quadratic complexity in WordDecoder.DecodeHeader in mime

Which CVE IDs does CVE-2026-42504 cover?

CVE-2026-42504 covers the following CVE IDs: CVE-2026-42504. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

What is the CVSS v3 score of CVE-2026-42504?

CVE-2026-42504 has a CVSS v3 base score of 7.5, published by Microsoft Security Response Center (MSRC).

Which products are affected by CVE-2026-42504?

CVE-2026-42504 affects 5 products, including: azl3 golang 1.25.10-1 on Azure Linux 3.0; azl3 golang 1.25.11-3 on Azure Linux 3.0; azl3 golang 1.26.3-1 on Azure Linux 3.0; azl3 golang 1.26.4-3 on Azure Linux 3.0; azl3 golang 1.27.0-1 on Azure Linux 3.0.

CVE-2026-42504HighCVSS 7.5

Quadratic complexity in WordDecoder.DecodeHeader in mime

Vendor

Microsoft Security Response Center (MSRC)

Published

June 9, 2026

Last Modified

—

🔗 CVE IDs covered (1)

CVE-2026-42504 →

🎯 Affected products5

azl3 golang 1.25.10-1 on Azure Linux 3.0
azl3 golang 1.25.11-3 on Azure Linux 3.0
azl3 golang 1.26.3-1 on Azure Linux 3.0
azl3 golang 1.26.4-3 on Azure Linux 3.0
azl3 golang 1.27.0-1 on Azure Linux 3.0

✅ Remediation

KBCBL-Mariner Releases (Security Update) — fixed build 1.26.4-1 Security Update

🔗 References (2)

advisoryhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42504
referencehttps://learn.microsoft.com/en-us/azure/azure-linux/tutorial-azure-linux-upgrade