#VU105654 Use-after-free in Linux kernel - CVE-2025-21858

Vulnerability identifier: #VU105654

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-2025-21858

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 geneve_destroy_tunnels() function in drivers/net/geneve.c. A local user can escalate privileges on the system.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Linux kernel: All versions

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External links
https://git.kernel.org/stable/c/3ce92ca990cfac88a87c61df3cc0b5880e688ecf
https://git.kernel.org/stable/c/788dbca056a8783ec063da3c9d49a3a71c76c283
https://git.kernel.org/stable/c/904e746b2e7fa952ab8801b303ce826a63153d78
https://git.kernel.org/stable/c/9593172d93b9f91c362baec4643003dc29802929
https://git.kernel.org/stable/c/da9b0ae47f084014b1e4b3f31f70a0defd047ff3

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Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.