CVE-2026-97602
HighCVSS 7.8Summary
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-2026-98162Unknown
In the Linux kernel, the smb2_tree_connect() function of the SMB server (ksmbd) leaks a tree connection. When ksmbd_iov_pin_rsp() fails, the newly created tree connection is not disconnected, leading to a resource leak.
- CVE-2026-98161Unknown
In the Linux kernel, the nvdimm (pmem) pmem_submit_bio() function records a REQ_PREFLUSH error but continues to copy bio data and can later overwrite the error with a successful REQ_FUA flush. This allows data writes to run after a failed preflush and can complete the bio successfully despite the failed ordering barrier.
- CVE-2026-98160Unknown
In the Linux kernel, the staging rtl8723bs driver's rtw_sdio_if1_init() function frees padapter->HalData with kfree(), even though it was allocated via vzalloc(). Using kfree() to release a vmalloc-backed buffer can lead to memory corruption.
- CVE-2026-100079Unknown
In the Linux kernel, the USB Type-C (ucsi) subsystem's ucsi_register() creates per-instance debugfs entries, but ucsi_unregister() keeps them until ucsi_destroy(). Drivers like ucsi_glink that unregister/register the same UCSI instance across remoteproc restart then try to create an already existing debugfs directory.
- CVE-2026-100078Unknown
In the Linux kernel, the iwlwifi (mei) driver's iwl_mei_write_cyclic_buf() function receives an incorrect first argument — the q_head pointer is passed instead of cldev. The bug has been fixed.
- CVE-2026-100077Unknown
In the Linux kernel, the drm/msm driver does not safely retire a hung submit before GPU recovery completes. Retiring the submit triggers BO free, which can result in GPU pagefaults since the GPU may be actively accessing those BOs.
- CVE-2026-100074Unknown
In the Linux kernel, a bug was fixed where the BPF_REFCOUNT field was not marked as unique, although it should be. The fix addresses this oversight.
- CVE-2026-100073Unknown
In the Linux kernel, a bug in the ext4 filesystem related to transaction overflow during writeback was fixed. A previous fix was too eager in reducing reserved transaction credits, leading to insufficient reservation in some corner cases. The fix uses ext4_meta_trans_blocks() for a correct upper bound estimate.
- CVE-2026-100072Unknown
In the Linux kernel, a problem in the ACPI subsystem was fixed where the use of acpi_get_first_physical_node() in acpi_platform_fill_resource() and acpi_create_platform_device() was unsafe because the returned device could be freed at any time. The fix replaces it with acpi_bus_get_primary_device() and adjusts the code to call it only once.
- CVE-2026-100071Unknown
In the Linux kernel, a memory leak in the HSR (High-availability Seamless Redundancy) module was fixed. When hsr_dev_finalize() fails after registering an RX handler, dynamic nodes learned in that window are not released. The fix frees both dynamic databases in the error unwind path.
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