What is CVE-2025-39873?

CVE-2025-39873 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10, classified as a Use After Free flaw (CWE-416), affecting Linux kernel versions from 4.19 onward and patched in 5.15.194, 6.1.153, 6.6.107 and others. CVE-2025-39873 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2025-39873?

CVE-2025-39873 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-2025-39873?

Yes, CVE-2025-39873 has been patched. Fixed versions include 5.15.194, 6.1.153, 6.6.107 and others. If you are running Linux kernel 4.19 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2025-39873 actively exploited?

CVE-2025-39873 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is Use After Free (CWE-416)?

The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. See MITRE CWE for full details: https://cwe.mitre.org/data/definitions/416.html

CVE-2025-39873

High

In the Linux kernel, the following vulnerability has been resolved: can: xilinx_can: xcan_write_frame(): fix use-after-free of transmitted SKB can_put_echo_skb() takes ownership of the SKB and it may be freed during or after the call. However, xilinx_can xcan_write_frame() keeps using SKB after the call. Fix that by only calling can_put_echo_skb() after the code is done touching the SKB. The tx_lock is held for the entire xcan_write_frame() execution and also on the can_get_echo_skb() side so the order of operations does not matter. An earlier fix commit 3d3c817c3a40 ("can: xilinx_can: Fix usage of skb memory") did not move the can_put_echo_skb() call far enough. [mkl: add "commit" in front of sha1 in patch description] [mkl: fix indention]

Package Linux Kernel

Published 2025-09-23

Last modified 2026-01-20

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-416

CVE-2025-39873 is a Use After Free vulnerability

What is Use After Free?

The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. Learn more on MITRE CWE

Affected versions

Linux kernel versions 4.19 and later are affected. Fixed in 5.15.194, 6.1.153, 6.6.107, 6.12.48, 6.16.8, 6.17 and their respective stable series.

Affected from

≥ 4.19

Fixed in

✓ 5.15.194 5.15.x ✓ 6.1.153 6.1.x ✓ 6.6.107 6.6.x ✓ 6.12.48 6.12.x ✓ 6.16.8 6.16.x ✓ 6.17

References

7 total

Kernel Git
https://git.kernel.org/stable/c/1139321161a3ba5e45e61e0738b37f42f20bc57a

Patch
Kernel Git
https://git.kernel.org/stable/c/668cc1e3bb21101d074e430de1b7ba8fd10189e7

Patch
Kernel Git
https://git.kernel.org/stable/c/725b33deebd6e4c96fe7893f384510a54258f28f

Patch
Kernel Git
https://git.kernel.org/stable/c/94b050726288a56a6b8ff55aa641f2fedbd3b44c

Patch
Kernel Git
https://git.kernel.org/stable/c/e202ffd9e54538ef67ec301ebd6d9da4823466c9

Patch

Showing 5 of 7 references View all on NVD

Details

CVE ID CVE-2025-39873

Severity High

CVSS score 7.8 / 10

CVSS version 3.1

Published 2025-09-23

Modified 2026-01-20

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2025-39873?

CVE-2025-39873 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 , classified as an Use After Free flaw (CWE-416) . It affects Linux kernel versions from 4.19 onward and has been patched in 5.15.194, 6.1.153, 6.6.107 and others. CVE-2025-39873 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2025-39873?

CVE-2025-39873 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-2025-39873?

Yes. CVE-2025-39873 has been patched. Fixed versions include 5.15.194, 6.1.153, 6.6.107 and others. If you are running Linux kernel 4.19 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2025-39873 actively exploited?

No. CVE-2025-39873 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.