CyberSecBulletin
CVE-2026-52975NVD status: Modified

Linux: Concurrent Execution using Shared Resource with Improper Synchronization

Published Updated By the CyberSecBulletin desk

CVE-2026-52975 is a high-severity concurrent execution using shared resource with improper synchronization vulnerability in Linux, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions ba2272be04f0cb1e74e1e355ff32ef95df280731, 3b7265b3a82f40d2357c4004b26eb794a095b186, 5fb9ea4e8ebf514d92df2b6c9d0db25ba02ac735 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.11% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to ba2272be04f0cb1e74e1e355ff32ef95df280731 or 3b7265b3a82f40d2357c4004b26eb794a095b186 or 5fb9ea4e8ebf514d92df2b6c9d0db25ba02ac735 or c169c5837525ad842df6a542facf52b6f866a519, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 6.1.175 or 6.6.141 or 6.12.95 or 6.18.33, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux47e91f56008b43e1365e8d1d4a6813fe8a33b6f6 up to, but not including, ba2272be04f0cb1e74e1e355ff32ef95df280731; 47e91f56008b43e1365e8d1d4a6813fe8a33b6f6 up to, but not including, 3b7265b3a82f40d2357c4004b26eb794a095b186; 47e91f56008b43e1365e8d1d4a6813fe8a33b6f6 up to, but not including, 5fb9ea4e8ebf514d92df2b6c9d0db25ba02ac735; 47e91f56008b43e1365e8d1d4a6813fe8a33b6f6 up to, but not including, c169c5837525ad842df6a542facf52b6f866a519; 47e91f56008b43e1365e8d1d4a6813fe8a33b6f6 up to, but not including, 78f409fd34fe9de2b24ad8e9dca1b4608a48ed3d; 47e91f56008b43e1365e8d1d4a6813fe8a33b6f6 up to, but not including, c4f050ce06c56cfb5993268af4a5cb66ed1cd04e; 3.13ba2272be04f0cb1e74e1e355ff32ef95df280731, 3b7265b3a82f40d2357c4004b26eb794a095b186, 5fb9ea4e8ebf514d92df2b6c9d0db25ba02ac735, c169c5837525ad842df6a542facf52b6f866a519, 78f409fd34fe9de2b24ad8e9dca1b4608a48ed3d, c4f050ce06c56cfb5993268af4a5cb66ed1cd04e
LinuxLinux Kernel3.13 up to, but not including, 6.1.175; 6.2 up to, but not including, 6.6.141; 6.7 up to, but not including, 6.12.95; 6.13 up to, but not including, 6.18.33; 6.19 up to, but not including, 7.0.10; 7.16.1.175, 6.6.141, 6.12.95, 6.18.33, 7.0.10

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA.

Official description

In the Linux kernel, the following vulnerability has been resolved: bonding: 3ad: implement proper RCU rules for port->aggregator syzbot found a data-race in bond_3ad_get_active_agg_info / bond_3ad_state_machine_handler [1] which hints at lack of proper RCU implementation. Add __rcu qualifier to port->aggregator, and add proper RCU API. [1] BUG: KCSAN: data-race in bond_3ad_get_active_agg_info / bond_3ad_state_machine_handler write to 0xffff88813cf5c4b0 of 8 bytes by task 36 on cpu 0: ad_port_selection_logic drivers/net/bonding/bond_3ad.c:1659 [inline] bond_3ad_state_machine_handler+0x9d5/0x2d60 drivers/net/bonding/bond_3ad.c:2569 process_one_work kernel/workqueue.c:3302 [inline] process_scheduled_works+0x4f0/0x9c0 kernel/workqueue.c:3385 worker_thread+0x58a/0x780 kernel/workqueue.c:3466 kthread+0x22a/0x280 kernel/kthread.c:436 ret_from_fork+0x146/0x330 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 read to 0xffff88813cf5c4b0 of 8 bytes by task 22063 on cpu 1: __bond_3ad_get_active_agg_info drivers/net/bonding/bond_3ad.c:2858 [inline] bond_3ad_get_active_agg_info+0x8c/0x230 drivers/net/bonding/bond_3ad.c:2881 bond_fill_info+0xe0f/0x10f0 drivers/net/bonding/bond_netlink.c:853 rtnl_link_info_fill net/core/rtnetlink.c:906 [inline] rtnl_link_fill+0x1d7/0x4e0 net/core/rtnetlink.c:927 rtnl_fill_ifinfo+0xf8e/0x1380 net/core/rtnetlink.c:2168 rtmsg_ifinfo_build_skb+0x11c/0x1b0 net/core/rtnetlink.c:4453 rtmsg_ifinfo_event net/core/rtnetlink.c:4486 [inline] rtmsg_ifinfo+0x6d/0x110 net/core/rtnetlink.c:4495 __dev_notify_flags+0x76/0x390 net/core/dev.c:9790 netif_change_flags+0xac/0xd0 net/core/dev.c:9823 do_setlink+0x905/0x2950 net/core/rtnetlink.c:3180 rtnl_group_changelink net/core/rtnetlink.c:3813 [inline] __rtnl_newlink net/core/rtnetlink.c:3981 [inline] rtnl_newlink+0xf55/0x1400 net/core/rtnetlink.c:4109 rtnetlink_rcv_msg+0x64b/0x720 net/core/rtnetlink.c:6995 netlink_rcv_skb+0x123/0x220 net/netlink/af_netlink.c:2550 rtnetlink_rcv+0x1c/0x30 net/core/rtnetlink.c:7022 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x5a8/0x680 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x5c8/0x6f0 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] ____sys_sendmsg+0x563/0x5b0 net/socket.c:2698 ___sys_sendmsg+0x195/0x1e0 net/socket.c:2752 __sys_sendmsg net/socket.c:2784 [inline] __do_sys_sendmsg net/socket.c:2789 [inline] __se_sys_sendmsg net/socket.c:2787 [inline] __x64_sys_sendmsg+0xd4/0x160 net/socket.c:2787 x64_sys_call+0x194c/0x3020 arch/x86/include/generated/asm/syscalls_64.h:47 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f value changed: 0x0000000000000000 -> 0xffff88813cf5c400 Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 22063 Comm: syz.0.31122 Tainted: G W syzkaller #0 PREEMPT(full) Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Concurrent Execution using Shared Resource with Improper Synchronization

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.

How developers prevent this class of flaw

  • In languages that support it, use synchronization primitives. Only wrap these around critical code to minimize the impact on performance.
  • Use thread-safe capabilities such as the data access abstraction in Spring.
  • Minimize the usage of shared resources in order to remove as much complexity as possible from the control flow and to reduce the likelihood of unexpected conditions occurring. Additionally, this will minimize the amount of synchronization necessary and may even help to reduce the likelihood of a denial of service where an attacker may be able to repeatedly trigger a critical section (CWE-400).

More Concurrent Execution using Shared Resource with Improper Synchronization vulnerabilities (CWE-362)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Concurrent Execution using Shared Resource with Improper Synchronization vulnerabilities

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