What is CVE-2025-21965?

CVE-2025-21965 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, classified as a NULL Pointer Dereference flaw (CWE-476). CVE-2025-21965 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2025-21965?

CVE-2025-21965 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-2025-21965?

No patch is currently available for CVE-2025-21965. Monitor the NIST NVD and your Linux distribution's security advisories for updates.

Is CVE-2025-21965 actively exploited?

CVE-2025-21965 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is NULL Pointer Dereference (CWE-476)?

The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. See MITRE CWE for full details: https://cwe.mitre.org/data/definitions/476.html

CVE-2025-21965

Medium

In the Linux kernel, the following vulnerability has been resolved: sched_ext: Validate prev_cpu in scx_bpf_select_cpu_dfl() If a BPF scheduler provides an invalid CPU (outside the nr_cpu_ids range) as prev_cpu to scx_bpf_select_cpu_dfl() it can cause a kernel crash. To prevent this, validate prev_cpu in scx_bpf_select_cpu_dfl() and trigger an scx error if an invalid CPU is specified.

Package Linux Kernel

Published 2025-04-01

Last modified 2025-10-31

CVSS version 3.1

Patch available

Awaiting data

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-476

CVE-2025-21965 is a NULL Pointer Dereference vulnerability

What is NULL Pointer Dereference?

The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. Learn more on MITRE CWE

References

The following references provide additional information about CVE-2025-21965 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/515680e76c536dd4aa8e2b5d674b0d441baddf5b
Patch
Kernel patch commit
https://git.kernel.org/stable/c/752b56bb76e2471197d25d6948d85753043b10da
Patch
Kernel patch commit
https://git.kernel.org/stable/c/9360dfe4cbd62ff1eb8217b815964931523b75b3
Patch

Details

CVE ID CVE-2025-21965

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2025-04-01

Modified 2025-10-31

KEV No

Patch Awaiting data

Package linux

Frequently asked questions

What is CVE-2025-21965?

CVE-2025-21965 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as a NULL Pointer Dereference flaw (CWE-476) . CVE-2025-21965 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2025-21965?

CVE-2025-21965 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-2025-21965?

No patch is currently available for CVE-2025-21965. Monitor the NIST NVD and your Linux distribution's security advisories for updates.
Is CVE-2025-21965 actively exploited?

No — CVE-2025-21965 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
What is NULL Pointer Dereference (CWE-476)?

The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. View CWE-476 on MITRE CWE →