What is CVE-2026-98255?

CVE-2026-98255 is a security advisory published by Microsoft Security Response Center (MSRC) with Critical severity. tcp: exclude old ACKs from tcp fast path

Which CVE IDs does CVE-2026-98255 cover?

CVE-2026-98255 covers the following CVE IDs: CVE-2026-98255. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

What is the CVSS v3 score of CVE-2026-98255?

CVE-2026-98255 has a CVSS v3 base score of 9.8, published by Microsoft Security Response Center (MSRC).

Which products are affected by CVE-2026-98255?

CVE-2026-98255 affects 1 product, including: azl3 kernel 6.6.157.1-1 on Azure Linux 3.0.

CVE-2026-98255CriticalCVSS 9.8

tcp: exclude old ACKs from tcp fast path

Vendor

Microsoft Security Response Center (MSRC)

Published

October 7, 2026

Last Modified

—

🔗 CVE IDs covered (1)

CVE-2026-98255 →

🎯 Affected products1

azl3 kernel 6.6.157.1-1 on Azure Linux 3.0

✅ Remediation

KBRelease Notes (Security Update) — fixed build 6.6.158.1-1

🔗 References (2)

advisoryhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-98255
referencehttps://learn.microsoft.com/en-us/azure/azure-linux/tutorial-azure-linux-upgrade