#VU104946 Use-after-free in Linux kernel - CVE-2025-21759

Vulnerability identifier: #VU104946

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-2025-21759

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 mld_send_cr() and igmp6_send() functions in net/ipv6/mcast.c. A local user can escalate privileges on the system.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Linux kernel: 6.13 - 6.13.3

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External links
https://git.kernel.org/stable/c/087c1faa594fa07a66933d750c0b2610aa1a2946
https://git.kernel.org/stable/c/0bf8e2f3768629d437a32cb824149e6e98254381
https://git.kernel.org/stable/c/81b25a07ebf53f9ef4ca8f3d96a8ddb94561dd5a
https://git.kernel.org/stable/c/8e92d6a413feaf968a33f0b439ecf27404407458
https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.13.4

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Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?