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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.
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4 events from the most recent confirmed update back to the earliest known activity.
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.
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.
Microsoft added CVE-2026-23356 to its Security Update Guide, describing a fix for a DRBD logic bug in drbd_al_begin_io_nonblock().
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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Microsoft published a broad batch of Security Update Guide entries for Linux kernel flaws affecting memory management, networking, virtualization, device drivers, and subsystem input validation. The listed issues include use-after-free, NULL dereference, integer underflow, refcount underflow, information disclosure, and bounds-checking failures tracked as **`CVE-2026-31496`**, **`CVE-2026-31458`**, **`CVE-2026-31689`**, **`CVE-2026-31615`**, **`CVE-2026-31664`**, **`CVE-2026-31656`**, **`CVE-2026-31611`**, **`CVE-2026-31671`**, **`CVE-2026-31612`**, and others. Affected components span `nf_conntrack_expect`, `damon`, `edac_mc`, `renesas_usb3`, `xfrm`, `drm/i915`, `ksmbd`, `stmmac`, `tipc`, `mptcp`, `NFC`, `HID`, `KVM`, `mmc`, `x86/CPU`, `PCI endpoint`, `blk-cgroup`, `media/as102`, and `altera-tse`. Several entries point to bugs that could lead to kernel crashes, memory corruption, or data leakage if triggered through malformed input, protocol handling, or device interaction. Notable examples include a slab use-after-free in `mptcp`, information leaks in `xfrm_user` and `xfrm`, validation flaws in `ksmbd`, endpoint index handling in `usb: gadget: renesas_usb3`, and multiple underflow and teardown-ordering bugs across networking and driver code. The disclosures indicate a coordinated publication of upstream Linux kernel fixes through Microsoft's advisory channel, underscoring the need for organizations running Linux workloads in Microsoft-connected environments to review affected kernel versions and apply vendor patches promptly.
Jul 12, 2026
Microsoft published a batch of Security Update Guide entries for Linux kernel vulnerabilities spanning core subsystems including `ext4`, `xfs`, memory management, networking, virtualization, and device drivers. The listed issues include memory-safety and stability flaws such as a use-after-free in `ext4` tracked as **CVE-2026-31446**, an `smc` double-free in **CVE-2026-31507**, a teardown-order use-after-free in the `spi-fsl-lpspi` driver in **CVE-2026-31485**, and a Bluetooth `L2CAP` bug in **CVE-2026-31498** that could trigger an infinite loop. Additional entries cover fixes in `af_key`, `netfilter` `ctnetlink`, `nfc` `nci`, `perf`, and memory-management code paths. The disclosures also include filesystem and virtual networking fixes such as **CVE-2026-31452** in `ext4`, **CVE-2026-31454** in `xfs`, and two `openvswitch` issues, **CVE-2026-31678** and **CVE-2026-31679`, addressing tunnel device release handling and MPLS payload-length validation. Microsoft further listed **CVE-2026-31601** in `vfio/xe` and **CVE-2026-31589** in the kernel MM subsystem, indicating broad exposure across Linux environments that rely on affected kernel components. The set of advisories points to patch activity focused on preventing use-after-free, double-free, locking, validation, and resource-lifecycle errors in widely deployed kernel code.
Jul 12, 2026
Microsoft added several CVEs to its Security Update Guide for Linux kernel components, including **CVE-2026-31609** in SMB, **CVE-2026-31591** in KVM SEV/SNP handling, **CVE-2026-31469** in `virtio_net`, **CVE-2026-31525** in BPF, and **CVE-2026-31494** in the `macb` network driver. The listed issues span memory-safety and logic flaws such as a double-free in `smbd_free_send_io()` after `smbd_send_batch_flush()`, a use-after-free in `virtio_net`, and undefined behavior in the BPF interpreter for signed division and modulo involving `INT_MIN`. The disclosures also include a KVM fix that locks all vCPUs while synchronizing VMSAs during SEV-SNP launch completion, indicating impact in confidential computing and virtualization workflows, alongside a `macb` driver correction for queue statistics handling. Taken together, the entries show Microsoft tracking upstream Linux kernel vulnerabilities across file sharing, virtualization, packet processing, and network drivers, with several bugs carrying potential stability or security impact in environments running affected kernel code paths.
Jul 12, 2026