Microsoft Discloses Linux Kernel Flaws in Bridge and DRBD Components
Microsoft published security advisories for two Linux kernel vulnerabilities tracked as CVE-2026-23381 and CVE-2026-23356. The first affects the networking stack's bridge code, where nd_tbl can be dereferenced as NULL when IPv6 is disabled, creating a stability and potential denial-of-service risk in affected systems.
The second advisory covers a logic bug in the Distributed Replicated Block Device (DRBD) subsystem, specifically in drbd_al_begin_io_nonblock(). Together, the disclosures highlight flaws in both kernel networking and storage-replication paths that administrators should review in Microsoft-tracked update guidance and remediate through available vendor patches.
Timeline
Mar 27, 2026
Microsoft publishes advisory for CVE-2026-23397
Microsoft added CVE-2026-23397 to its Security Update Guide, describing a fix related to nfnetlink_osf and validation of individual option lengths in fingerprints.
Mar 26, 2026
Microsoft publishes advisory for CVE-2026-23381
Microsoft added CVE-2026-23381 to its Security Update Guide, describing a fix for a net/bridge nd_tbl NULL dereference issue when IPv6 is disabled.
Mar 26, 2026
Microsoft publishes advisory for CVE-2026-23356
Microsoft added CVE-2026-23356 to its Security Update Guide, describing a fix for a DRBD logic bug in drbd_al_begin_io_nonblock().
Mar 26, 2026
Microsoft publishes advisory for CVE-2026-23293
Microsoft added CVE-2026-23293 to its Security Update Guide, describing a fix for a VXLAN nd_tbl NULL dereference issue when IPv6 is disabled.
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