What is CVE-2025-39809?

CVE-2025-39809 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10, classified as a Out-of-bounds Write flaw (CWE-787), affecting Linux kernel versions from 6.14 onward and patched in 6.16.5 and 6.17. CVE-2025-39809 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2025-39809?

CVE-2025-39809 has a CVSS score of 7.8 out of 10, rated High severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Is there a patch available for CVE-2025-39809?

Yes, CVE-2025-39809 has been patched. Fixed versions include 6.16.5 and 6.17. If you are running Linux kernel 6.14 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2025-39809 actively exploited?

CVE-2025-39809 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is Out-of-bounds Write (CWE-787)?

The product writes data past the end or before the beginning of the intended buffer. See MITRE CWE for full details: https://cwe.mitre.org/data/definitions/787.html

CVE-2025-39809

High

In the Linux kernel, the following vulnerability has been resolved: HID: intel-thc-hid: intel-quicki2c: Fix ACPI dsd ICRS/ISUB length The QuickI2C ACPI _DSD methods return ICRS and ISUB data with a trailing byte, making the actual length is one more byte than the structs defined. It caused stack-out-of-bounds and kernel crash: kernel: BUG: KASAN: stack-out-of-bounds in quicki2c_acpi_get_dsd_property.constprop.0+0x111/0x1b0 [intel_quicki2c] kernel: Write of size 12 at addr ffff888106d1f900 by task kworker/u33:2/75 kernel: kernel: CPU: 3 UID: 0 PID: 75 Comm: kworker/u33:2 Not tainted 6.16.0+ #3 PREEMPT(voluntary) kernel: Workqueue: async async_run_entry_fn kernel: Call Trace: kernel: <TASK> kernel: dump_stack_lvl+0x76/0xa0 kernel: print_report+0xd1/0x660 kernel: ? __pfx__raw_spin_lock_irqsave+0x10/0x10 kernel: ? __kasan_slab_free+0x5d/0x80 kernel: ? kasan_addr_to_slab+0xd/0xb0 kernel: kasan_report+0xe1/0x120 kernel: ? quicki2c_acpi_get_dsd_property.constprop.0+0x111/0x1b0 [intel_quicki2c] kernel: ? quicki2c_acpi_get_dsd_property.constprop.0+0x111/0x1b0 [intel_quicki2c] kernel: kasan_check_range+0x11c/0x200 kernel: __asan_memcpy+0x3b/0x80 kernel: quicki2c_acpi_get_dsd_property.constprop.0+0x111/0x1b0 [intel_quicki2c] kernel: ? __pfx_quicki2c_acpi_get_dsd_property.constprop.0+0x10/0x10 [intel_quicki2c] kernel: quicki2c_get_acpi_resources+0x237/0x730 [intel_quicki2c] [...] kernel: </TASK> kernel: kernel: The buggy address belongs to stack of task kworker/u33:2/75 kernel: and is located at offset 48 in frame: kernel: quicki2c_get_acpi_resources+0x0/0x730 [intel_quicki2c] kernel: kernel: This frame has 3 objects: kernel: [32, 36) 'hid_desc_addr' kernel: [48, 59) 'i2c_param' kernel: [80, 224) 'i2c_config' ACPI DSD methods return: \_SB.PC00.THC0.ICRS Buffer 000000003fdc947b 001 Len 0C = 0A 00 80 1A 06 00 00 00 00 00 00 00 \_SB.PC00.THC0.ISUB Buffer 00000000f2fcbdc4 001 Len 91 = 00 00 00 00 00 00 00 00 00 00 00 00 Adding reserved padding to quicki2c_subip_acpi_parameter/config.

Package Linux Kernel

Published 2025-09-16

Last modified 2026-01-14

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

7.8

out of 10

High

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Vector string

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

Weakness type

CWE-787

CVE-2025-39809 is a Out-of-bounds Write vulnerability

What is Out-of-bounds Write?

The product writes data past the end or before the beginning of the intended buffer. Learn more on MITRE CWE

Affected versions

Linux kernel versions 6.14 and later are affected. Fixed in 6.16.5, 6.17 and their respective stable series.

Affected from

≥ 6.14

Fixed in

✓ 6.16.5 6.16.x ✓ 6.17

References

The following references provide additional information about CVE-2025-39809 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Kernel patch commit
https://git.kernel.org/stable/c/1db9df89a213318a48d958385dc1b17b379dc32b
Patch
Kernel patch commit
https://git.kernel.org/stable/c/4adce86d4b13d15dec7810967839b931b1598700
Patch

Details

CVE ID CVE-2025-39809

Severity High

CVSS score 7.8 / 10

CVSS version 3.1

Published 2025-09-16

Modified 2026-01-14

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2025-39809?

CVE-2025-39809 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 , classified as an Out-of-bounds Write flaw (CWE-787) . It affects Linux kernel versions from 6.14 onward and has been patched in 6.16.5 and 6.17. CVE-2025-39809 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2025-39809?

CVE-2025-39809 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
Is there a patch available for CVE-2025-39809?

Yes — CVE-2025-39809 has been patched. Fixed versions include 6.16.5 and 6.17. If you are running Linux kernel 6.14 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2025-39809 actively exploited?

No — CVE-2025-39809 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
What is Out-of-bounds Write (CWE-787)?

The product writes data past the end or before the beginning of the intended buffer. View CWE-787 on MITRE CWE →