#VU104961 Use-after-free in Linux kernel - CVE-2025-21726

Vulnerability identifier: #VU104961

Vulnerability risk: Low

CVSSv4.0: 5.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2025-21726

CWE-ID: CWE-416

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Linux kernel
Operating systems & Components / Operating system

Vendor: Linux Foundation

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a use-after-free error within the padata_reorder() and invoke_padata_reorder() functions in kernel/padata.c. A local user can escalate privileges on the system.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Linux kernel: 5.10 - 5.10.234, 5.15 - 5.15.178, 6.1 - 6.1.128, 6.6 - 6.6.75, 6.12 - 6.12.12, 6.13 - 6.13.1

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External links
https://git.kernel.org/stable/c/6f45ef616775b0ce7889b0f6077fc8d681ab30bc
https://git.kernel.org/stable/c/7000507bb0d2ceb545c0a690e0c707c897d102c2
https://git.kernel.org/stable/c/8ca38d0ca8c3d30dd18d311f1a7ec5cb56972cac
https://git.kernel.org/stable/c/a54091c24220a4cd847d5b4f36d678edacddbaf0
https://git.kernel.org/stable/c/dd7d37ccf6b11f3d95e797ebe4e9e886d0332600
https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.10.235
https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.15.179
https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.1.129
https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.12.13
https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.13.2
https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.14
https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.6.76

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Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?