What is CVE-2025-39888?

CVE-2025-39888 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 6.16 onward and patched in 6.16.8 and 6.17. CVE-2025-39888 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2025-39888?

CVE-2025-39888 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-2025-39888?

Yes, CVE-2025-39888 has been patched. Fixed versions include 6.16.8 and 6.17. If you are running Linux kernel 6.16 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2025-39888 actively exploited?

CVE-2025-39888 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-2025-39888

High

In the Linux kernel, the following vulnerability has been resolved: fuse: Block access to folio overlimit syz reported a slab-out-of-bounds Write in fuse_dev_do_write. When the number of bytes to be retrieved is truncated to the upper limit by fc->max_pages and there is an offset, the oob is triggered. Add a loop termination condition to prevent overruns.

Package Linux Kernel

Published 2025-09-23

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-2025-39888 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 6.16 and later are affected. Fixed in 6.16.8, 6.17 and their respective stable series.

Affected from

≥ 6.16

Fixed in

✓ 6.16.8 6.16.x ✓ 6.17

References

The following references provide additional information about CVE-2025-39888 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/623719227b114d73a2cee45f1b343ced63ce09ec
Patch
Kernel patch commit
https://git.kernel.org/stable/c/9d81ba6d49a7457784f0b6a71046818b86ec7e44
Patch

Details

CVE ID CVE-2025-39888

Severity High

CVSS score 7.8 / 10

CVSS version 3.1

Published 2025-09-23

Modified 2026-01-14

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2025-39888?

CVE-2025-39888 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 6.16 onward and has been patched in 6.16.8 and 6.17. CVE-2025-39888 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2025-39888?

CVE-2025-39888 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-2025-39888?

Yes — CVE-2025-39888 has been patched. Fixed versions include 6.16.8 and 6.17. If you are running Linux kernel 6.16 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2025-39888 actively exploited?

No — CVE-2025-39888 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 →