What is CVE-2025-21963?

CVE-2025-21963 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, classified as a Integer Overflow flaw (CWE-190), affecting Linux kernel versions from 5.12 onward and patched in 5.15.180, 6.1.132, 6.6.84 and others. CVE-2025-21963 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2025-21963?

CVE-2025-21963 has a CVSS score of 5.5 out of 10, rated Medium severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Is there a patch available for CVE-2025-21963?

Yes, CVE-2025-21963 has been patched. Fixed versions include 5.15.180, 6.1.132, 6.6.84 and others. If you are running Linux kernel 5.12 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2025-21963 actively exploited?

CVE-2025-21963 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is Integer Overflow (CWE-190)?

The product performs a calculation that can produce an integer overflow, leading to unexpected values. See MITRE CWE for full details: https://cwe.mitre.org/data/definitions/190.html

CVE-2025-21963

Medium

In the Linux kernel, the following vulnerability has been resolved: cifs: Fix integer overflow while processing acdirmax mount option User-provided mount parameter acdirmax of type u32 is intended to have an upper limit, but before it is validated, the value is converted from seconds to jiffies which can lead to an integer overflow. Found by Linux Verification Center (linuxtesting.org) with SVACE.

Package Linux Kernel

Published 2025-04-01

Last modified 2025-11-03

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

5.5

out of 10

Medium

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

High

Vector string

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

Weakness type

CWE-190

CVE-2025-21963 is a Integer Overflow vulnerability

What is Integer Overflow?

The product performs a calculation that can produce an integer overflow, leading to unexpected values. Learn more on MITRE CWE

Affected versions

Linux kernel versions 5.12 and later are affected. Fixed in 5.15.180, 6.1.132, 6.6.84, 6.12.20, 6.13.8, 6.14 and their respective stable series.

Affected from

≥ 5.12

Fixed in

✓ 5.15.180 5.15.x ✓ 6.1.132 6.1.x ✓ 6.6.84 6.6.x ✓ 6.12.20 6.12.x ✓ 6.13.8 6.13.x ✓ 6.14

References

7 total

Kernel Git
https://git.kernel.org/stable/c/0c26edf477e093cefc41637f5bccc102e1a77399

Patch
Kernel Git
https://git.kernel.org/stable/c/2809a79bc64964ce02e0c5f2d6bd39b9d09bdb3c

Patch
Kernel Git
https://git.kernel.org/stable/c/39d086bb3558da9640ef335f97453e01d32578a1

Patch
Kernel Git
https://git.kernel.org/stable/c/5b29891f91dfb8758baf1e2217bef4b16b2b165b

Patch
Kernel Git
https://git.kernel.org/stable/c/6124cbf73e3dea7591857dd63b8ccece28952afd

Patch

Showing 5 of 7 references View all on NVD

Details

CVE ID CVE-2025-21963

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2025-04-01

Modified 2025-11-03

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2025-21963?

CVE-2025-21963 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as an Integer Overflow flaw (CWE-190) . It affects Linux kernel versions from 5.12 onward and has been patched in 5.15.180, 6.1.132, 6.6.84 and others. CVE-2025-21963 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2025-21963?

CVE-2025-21963 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
Is there a patch available for CVE-2025-21963?

Yes. CVE-2025-21963 has been patched. Fixed versions include 5.15.180, 6.1.132, 6.6.84 and others. If you are running Linux kernel 5.12 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2025-21963 actively exploited?

No. CVE-2025-21963 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.