Linux KernelOperating system · Linux

CVE-2025-39818

HIGH · 7.8 CVSS v3.1 Published 2025-09-16
Fix available
A fix is available. Upgrade to 6.16.5 or later.
See remediation →
80/100
Remediation priority · High
Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
In the Linux kernel, the following vulnerability has been resolved: HID: intel-thc-hid: intel-thc: Fix incorrect pointer arithmetic in I2C regs save Improper use of secondary pointer (&dev->i2c_subip_regs) caused kernel crash and out-of-bounds error: BUG: KASAN: slab-out-of-bounds in _regmap_bulk_read+0x449/0x510 Write of size 4 at addr ffff888136005dc0 by task kworker/u33:5/5107 CPU: 3 UID: 0 PID: 5107 Comm: kworker/u33:5 Not tainted 6.16.0+ #3 PREEMPT(voluntary) Workqueue: async async_run_entry_fn Call Trace: <TASK> dump_stack_lvl+0x76/0xa0 print_report+0xd1/0x660 ? __pfx__raw_spin_lock_irqsave+0x10/0x10 ? kasan_complete_mode_report_info+0x26/0x200 kasan_report+0xe1/0x120 ? _regmap_bulk_read+0x449/0x510 ? _regmap_bulk_read+0x449/0x510 __asan_report_store4_noabort+0x17/0x30 _regmap_bulk_read+0x449/0x510 ? __pfx__regmap_bulk_read+0x10/0x10 regmap_bulk_read+0x270/0x3d0 pio_complete+0x1ee/0x2c0 [intel_thc] ? __pfx_pio_complete+0x10/0x10 [intel_thc] ? __pfx_pio_wait+0x10/0x10 [intel_thc] ? regmap_update_bits_base+0x13b/0x1f0 thc_i2c_subip_pio_read+0x117/0x270 [intel_thc] thc_i2c_subip_regs_save+0xc2/0x140 [intel_thc] ? __pfx_thc_i2c_subip_regs_save+0x10/0x10 [intel_thc] [...] The buggy address belongs to the object at ffff888136005d00 which belongs to the cache kmalloc-rnd-12-192 of size 192 The buggy address is located 0 bytes to the right of allocated 192-byte region [ffff888136005d00, ffff888136005dc0) Replaced with direct array indexing (&dev->i2c_subip_regs[i]) to ensure safe memory access.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-787

The program writes past the bounds of a buffer, overwriting adjacent memory an attacker can turn to their advantage. Crafted input can overwrite control data and redirect execution. Remediation is validating every index and length before a write, plus modern memory-safety mitigations.

General guidance for the out-of-bounds write class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Linux KernelOperating system
Affected:>= 6.14, < 6.16.5= 6.17

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 6.16.5 or later
Fixed in 6.16.5
Vendor patch git.kernel.org →
Recommended fix High confidence

Linux Kernel 6.16.5 or later stable release

  1. Identify the current kernel version using 'uname -r' or 'cat /proc/version'
  2. Check if the system runs a vulnerable kernel version (>= 6.14, < 6.16.5, or = 6.17)
  3. For Debian/Ubuntu-based systems: run 'sudo apt update && sudo apt upgrade' to install the latest stable kernel package, or manually install linux-image-[version] from the distribution's repository
  4. For RHEL/CentOS/Fedora-based systems: run 'sudo dnf update kernel' or 'sudo yum update kernel'
  5. For systems building from source: download Linux kernel 6.16.5 or later from https://www.kernel.org/, extract the source, configure, compile, and install the new kernel
  6. Reboot the system into the new kernel using 'sudo reboot'
  7. Verify the fix is applied by checking 'uname -r' shows version >= 6.16.5 or by confirming the patched commit 78d4cf0466c79452e47aa6f720afbde63e709ccc is in the kernel build
Caveat Kernel upgrades may require rebuilding out-of-tree kernel modules; ensure third-party drivers (especially Intel THC hardware support) are compatible with the new kernel version

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $3,200. Get the upgrade done

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-39818 in production — separate from our analysis above.

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What this is

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