CVE-2026-97602
HighCVSS 7.8Exploitation Probability (EPSS)
Low risk4th percentile - higher than 4% of all known CVEs
Summary
A vulnerability in the Linux kernel's IPv6 packet fragmentation mechanism (inet: frags) was found. Improper flushing of fragment queues before their removal can lead to use of stale metadata, resulting in out-of-bounds access and heap corruption. An attacker with access to unprivileged network namespaces can exploit this for local privilege escalation.
Risk Assessment
The risk includes local privilege escalation on systems with unprivileged network namespaces enabled, potentially leading to full system compromise. Additionally, unflushed fragments may keep conntrack references alive after per-net cleanup, causing memory leaks or other issues.
Recommendation
Apply the official Linux kernel patch that fixes this vulnerability immediately. Until updated, restrict access to unprivileged network namespaces (e.g., via sysctl kernel.unprivileged_userns_clone=0) and monitor the system for unusual activity.
Other vulnerabilities in Linux kernel
See all- CVE-2026-99259Unknown
In the Linux kernel, the soc/tegra: pmc driver has an uninitialised early_pmc->rate variable for legacy 32-bit Tegra devices. The variable is never configured and remains 0, triggering a warning in tegra_pmc_enter_suspend_mode(). The issue appeared after the PMC driver was changed to create the PMC context dynamically, updating rate only in the new context.
- CVE-2026-99258Unknown
In the Linux kernel, hv_apicid_to_vp_index() uses per-CPU hypercall input and output pages. In an SEV-SNP CoCo VM without a paravisor the output page is not allocated, so the hypervisor stores the resulting VP index into memory not allocated by the guest. The fix uses the input page for both input and output.
- CVE-2026-99257Unknown
In the Linux kernel, the shared GPIO mechanism based on platform lookup tables requires an associated struct device. An fwnode-based lookup with no associated device currently causes a NULL-pointer dereference. The fix adds a check that lets the kernel gracefully handle this situation with an error.
- CVE-2026-99256Unknown
In the Linux kernel, the dm cache module used a rw_semaphore for background_work_lock, although write locks on rw_semaphores have strict owner semantics. The locking process was not always the same as the unlocking one, triggering a warning with CONFIG_DEBUG_RWSEMS during suspend/resume of a cache device. The fix replaces the rw_semaphore with a spinlock and a wait queue.
- CVE-2026-99251Unknown
In the Linux kernel, init_vp_index() contains a retry loop that strips CPUs from a node if they are already in the allocated cpumask or outside the HK_TYPE_MANAGED_IRQ housekeeping cpumask. If the housekeeping cpumask contains no CPU in that node, the loop becomes infinite. The fix skips NUMA nodes with no housekeeping CPU and aborts early when no online housekeeping CPUs exist.
- CVE-2026-99250Unknown
In the Linux kernel, the NBCON console printing kthreads are started very early during boot via early_initcall(). Asynchronously enabling/disabling interrupts during early boot may interfere with early SMP setup on some hardware platforms, causing hangs. The fix postpones kthread startup until after all arch initcalls have completed.
- CVE-2026-99249Unknown
In the Linux kernel, zap_pid_ns_processes() waiting for PID namespace cleanup was not freezable. A tracer outside the namespace that does not reap its traced zombies keeps PIDs allocated, making the wait unbounded and causing every suspend attempt to fail. The fix makes the wait loops use TASK_FREEZABLE states so the freezer can freeze waiting tasks.
- CVE-2026-99248Unknown
In the Linux kernel, the i2c: xiic driver was changed to restore non-managed runtime PM instead of the devres-based approach to fix a clk WARN flood. The managed release tore down runtime PM in the wrong order, causing the clock to be disabled twice and triggering "clkN already disabled" warnings on every teardown.
- CVE-2026-99247Unknown
In the Linux kernel, if trace buffer allocation fails during early boot, tracing_disabled remains set and the global trace array events list stays uninitialized. tracer_init_tracefs_work_func() runs asynchronously without checking this state and calls event_trace_init() and init_tracer_tracefs(), leading to a NULL pointer dereference Oops during boot. The fix checks tracing_disabled at the start of the work function.
- 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).
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: inet: frags: invalidate queues before flushing them fqdir_pre_exit() flushes the skbs from incomplete queues without changing their completion state. A fragment which found a queue before high_thresh was cleared can then acquire the queue lock and reuse stale reassembly metadata. A queue concurrently killed after fqdir->dead is set can instead become INET_FRAG_COMPLETE|INET_FRAG_HASH_DEAD while still holding its old skbs; skipping it because it is complete leaves those references behind until asynchronous fqdir teardown. For IPv6, stale metadata can make ip6_frag_reasm() use the old nhoffset with a new skb and access memory out of bounds. The resulting heap corruption can be leveraged for local privilege escalation when unprivileged network namespaces are available. Unflushed fragments can also keep conntrack references alive after the conntrack per-net cleanup point. Kill each incomplete queue, then flush every queue still owned by the dying rhashtable. HASH_DEAD identifies that ownership, while complete queues without it are already owned by another destroy path and must be left alone. Releasing a timer reference removed by inet_frag_kill() is deferred to inet_frag_putn(), after the queue lock is dropped. KASAN report: BUG: KASAN: slab-out-of-bounds in ipv6_frag_rcv (net/ipv6/reassembly.c:289 (discriminator 2) net/ipv6/reassembly.c:229 (discriminator 2) net/ipv6/reassembly.c:391 (discriminator 2)) Write of size 1 at addr ff110001039c6e00 by task poc/771 Call Trace: ? ipv6_frag_rcv (net/ipv6/reassembly.c:289 (discriminator 2) net/ipv6/reassembly.c:229 (discriminator 2) net/ipv6/reassembly.c:391 (discriminator 2)) ipv6_frag_rcv (net/ipv6/reassembly.c:289 (discriminator 2) net/ipv6/reassembly.c:229 (discriminator 2) net/ipv6/reassembly.c:391 (discriminator 2)) ip6_protocol_deliver_rcu (net/ipv6/ip6_input.c:479 (discriminator 5)) ip6_input_finish (net/ipv6/ip6_input.c:534) ipv6_rcv (include/net/dst.h:480 (discriminator 3) net/ipv6/ip6_input.c:119 (discriminator 3) net/ipv6/ip6_input.c:109 (discriminator 3) include/linux/netfilter.h:325 (discriminator 3) include/linux/netfilter.h:319 (discriminator 3) net/ipv6/ip6_input.c:351 (discriminator 3)) packet_sendmsg (net/packet/af_packet.c:3110 net/packet/af_packet.c:3142) __x64_sys_sendmmsg (net/socket.c:2883 net/socket.c:2880 net/socket.c:2880) The buggy address belongs to the object at ff110001039c6b40 which belongs to the cache skbuff_small_head of size 704 The buggy address is located 0 bytes to the right of allocated 704-byte region [ff110001039c6b40, ff110001039c6e00) BUG: KASAN: slab-out-of-bounds in ip6_protocol_deliver_rcu (net/ipv6/ip6_input.c:423 (discriminator 1)) Read of size 1 at addr ff110001039c6e08 by task poc/771 Call Trace: ? ip6_protocol_deliver_rcu (net/ipv6/ip6_input.c:423 (discriminator 1)) ip6_protocol_deliver_rcu (net/ipv6/ip6_input.c:423 (discriminator 1)) ip6_input_finish (net/ipv6/ip6_input.c:534) ipv6_rcv (include/net/dst.h:480 (discriminator 3) net/ipv6/ip6_input.c:119 (discriminator 3) net/ipv6/ip6_input.c:109 (discriminator 3) include/linux/netfilter.h:325 (discriminator 3) include/linux/netfilter.h:319 (discriminator 3) net/ipv6/ip6_input.c:351 (discriminator 3)) packet_sendmsg (net/packet/af_packet.c:3110 net/packet/af_packet.c:3142) __x64_sys_sendmmsg (net/socket.c:2883 net/socket.c:2880 net/socket.c:2880) packet_sendmsg (net/packet/af_packet.c:2959 net/packet/af_packet.c:3053 net/packet/af_packet.c:3142) __x64_sys_sendmmsg (net/socket.c:2883 net/socket.c:2880 net/socket.c:2880) The buggy address belongs to the object at ff110001039c6b40 which belongs to the cache skbuff_small_head of size 704 The buggy address is located 8 bytes to the right of allocated 704-byte region [ff110001039c6b40, ff110001039c6e00)
Vulnerability data from NVD (NIST) · CISA KEV · EPSS