What is CVE-2025-40257?

CVE-2025-40257 is a security advisory published by Microsoft Security Response Center (MSRC) with Medium severity. mptcp: fix a race in mptcp_pm_del_add_timer()

Which CVE IDs does CVE-2025-40257 cover?

CVE-2025-40257 covers the following CVE IDs: CVE-2025-40257. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

What is the CVSS v3 score of CVE-2025-40257?

CVE-2025-40257 has a CVSS v3 base score of 6.3, published by Microsoft Security Response Center (MSRC).

Which products are affected by CVE-2025-40257?

CVE-2025-40257 affects 2 products, including: azl3 kernel 6.6.112.1-2 on Azure Linux 3.0; azl3 kernel 6.6.117.1-1 on Azure Linux 3.0.

CVE-2025-40257MediumCVSS 6.3

mptcp: fix a race in mptcp_pm_del_add_timer()

Vendor

Microsoft Security Response Center (MSRC)

Published

December 6, 2025

Last Modified

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🔗 CVE IDs covered (1)

CVE-2025-40257 →

🎯 Affected products2

azl3 kernel 6.6.112.1-2 on Azure Linux 3.0
azl3 kernel 6.6.117.1-1 on Azure Linux 3.0

✅ Remediation

KBCBL-Mariner Releases (Security Update) — fixed build 6.6.119.3-1

🔗 References (2)

advisoryhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-40257
referencehttps://learn.microsoft.com/en-us/azure/azure-linux/tutorial-azure-linux-upgrade