What is CVE-2026-23439?

CVE-2026-23439 is a security advisory published by Microsoft Security Response Center (MSRC) with Medium severity. udp_tunnel: fix NULL deref caused by udp_sock_create6 when CONFIG_IPV6=n

Which CVE IDs does CVE-2026-23439 cover?

CVE-2026-23439 covers the following CVE IDs: CVE-2026-23439. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

What is the CVSS v3 score of CVE-2026-23439?

CVE-2026-23439 has a CVSS v3 base score of 5.5, published by Microsoft Security Response Center (MSRC).

Which products are affected by CVE-2026-23439?

CVE-2026-23439 affects 2 products, including: cbl2 kernel 5.15.202.1-1 on CBL Mariner 2.0; cbl2 kernel 5.15.202.1-1 on CBL-Mariner 2.0.

CVE-2026-23439MediumCVSS 5.5

udp_tunnel: fix NULL deref caused by udp_sock_create6 when CONFIG_IPV6=n

Vendor

Microsoft Security Response Center (MSRC)

Published

June 2, 2026

Last Modified

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🔗 CVE IDs covered (1)

CVE-2026-23439 →

🎯 Affected products2

cbl2 kernel 5.15.202.1-1 on CBL Mariner 2.0
cbl2 kernel 5.15.202.1-1 on CBL-Mariner 2.0

✅ Remediation

KBRelease Notes (Security Update)

🔗 References (2)

advisoryhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-23439
referencehttps://learn.microsoft.com/en-us/azure/azure-linux/tutorial-azure-linux-upgrade