CVE-2026-74715
HighCVSS 7.8Exploitation Probability (EPSS)
Low risk2th percentile - higher than 2% of all known CVEs
Summary
A vulnerability in the Linux kernel's BPF conntrack kfuncs was found, where the opts argument can point to a shared map value. Inconsistent reads of the netns_id field during acquisition and release of network namespace references can lead to reference imbalance, potentially destroying a live namespace and crashing the system.
Risk Assessment
An attacker with privileges to run BPF programs could cause kernel integrity issues, leading to a system crash (kernel panic) or potentially exploiting the bug for privilege escalation. The reference imbalance may also enable a denial-of-service attack at the kernel level.
Recommendation
Apply the official Linux kernel patch that fixes this issue immediately and update the system to a patched kernel version. Also restrict BPF functionality to trusted processes only.
Other vulnerabilities in Linux kernel
See all- CVE-2026-99215Unknown
In the Linux kernel power supply subsystem, a use-after-free vulnerability exists. If a power supply is unregistered while its external_power_changed() callback is still running, the driver may free data that the callback is still accessing, leading to a kernel crash (NULL pointer dereference).
- CVE-2026-99210Unknown
In the Linux kernel accel/rocket driver, rocket_probe() stores the return value of rocket_device_init() in the file-scoped rdev pointer before checking whether it is an error pointer. On failure rdev remains an ERR_PTR, and a later probe can skip initialization and dereference the error pointer when reading rdev->num_cores.
- CVE-2026-99209Unknown
In the Linux kernel drm/xe driver, xe_evict_flags() reads tbo->resource->mem_type, but a BO can reach eviction with no ttm.resource, e.g. an imported dma-buf whose resource was freed during teardown. This causes a NULL pointer dereference and a kernel fault.
- CVE-2026-99208Unknown
In the Linux kernel drm/xe/oa driver, ttm_bo_type_kernel BOs are not guaranteed to be zeroed on allocation and may contain data from previously freed pages. Since the OA buffer is mmap'able by userspace, this can expose stale kernel memory contents.
- CVE-2026-99207Unknown
In the Linux kernel's scsi: target subsystem, target_do_delayed_work() acquired delayed_cmd_lock with a plain spin_lock() without disabling interrupts, while all other acquisition sites use spin_lock_irqsave(). Since commands can now complete in interrupt context (complete_type=1 with direct_compl_supp), this can cause a deadlock when a completion arrives on the same CPU where the work item holds the lock.
- CVE-2026-99205Unknown
In the Linux kernel, a race exists in sched_change_end() with __sched_setscheduler() for queued but non-running tasks. When a task's scheduling class changes (e.g., from SCHED_OTHER to SCHED_RR), rq->next_class is not updated and the need-resched indicator is not set, causing the CPU to idle despite a runnable task being present.
- CVE-2026-99200Unknown
In the Linux kernel, the hisi_femac network driver (net: hisilicon) assigns netdev_ops only after connecting the PHY. With CONFIG_NET_SHAPER enabled, phy_attach_direct() reads uninitialized netdev_ops, causing a kernel panic from a NULL pointer dereference.
- CVE-2026-99199Unknown
In the Linux kernel, the hip04_eth network driver (net: hisilicon) calls of_phy_connect() before ndev->netdev_ops is assigned. With CONFIG_NET_SHAPER enabled, phy_attach_direct() reads uninitialized netdev_ops, causing a kernel panic from a NULL pointer dereference.
- CVE-2026-99198Unknown
In the Linux kernel, the owl_emac network driver (net: ethernet: actions) calls owl_emac_phy_init(), which connects the PHY, before netdev->netdev_ops is assigned. With CONFIG_NET_SHAPER enabled, phy_attach_direct() reads uninitialized netdev_ops, causing a kernel panic from a NULL pointer dereference.
- CVE-2026-99197Unknown
In the Linux kernel, the mv643xx_eth network driver connects the PHY before dev->netdev_ops is assigned. With CONFIG_NET_SHAPER enabled, phy_attach_direct() reads uninitialized netdev_ops, causing a kernel panic from a NULL pointer dereference.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: bpf: Fix netns reference imbalance in conntrack kfuncs The opts argument of the BPF conntrack kfuncs can point to a shared map value. __bpf_nf_ct_lookup() and __bpf_nf_ct_alloc_entry() read opts->netns_id separately when acquiring and releasing the network namespace reference. The reference imbalance can occur as follows: CPU 0 CPU 1 read opts->netns_id (-1) skip get_net_ns_by_id() write opts->netns_id (id) read opts->netns_id (id) put_net(net) /* no matching get */ The reverse transition leaks the reference. Repeating the unmatched put can destroy a live namespace and crash later users. The kernel reported: Oops: general protection fault, probably for non-canonical address KASAN: null-ptr-deref in range [0x00000000000000e8-0x00000000000000ef] RIP: 0010:bpf_prog_test_run_xdp+0x52c/0x1700 Call Trace: __sys_bpf+0x1662/0x50c0 __x64_sys_bpf+0x73/0xb0 do_syscall_64+0xf9/0x540 entry_SYSCALL_64_after_hwframe+0x77/0x7f Kernel panic - not syncing: Fatal exception Snapshot every input field of opts with READ_ONCE() before validating or using it. The netns_id snapshot keeps the namespace get/put pair balanced, while the other snapshots keep the remaining options from changing partway through an invocation. The individual reads can still observe an inconsistent combination during a concurrent update, but each selected field value remains stable for that invocation.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS

