Use-after-free in Linux kernel io_uring

1) Use-after-free

EUVDB-ID: #VU103012

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-2025-21633

CWE-ID: CWE-416 - Use After Free

Exploit availability: No

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 io_sq_thread() function in io_uring/sqpoll.c. A local user can escalate privileges on the system.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Linux kernel: All versions

CPE2.3

• cpe:2.3:o:linux_foundation:linux_kernel:*:*:*:*:*:*:*:*

External links

https://git.kernel.org/stable/c/4b7cfa8b6c28a9fa22b86894166a1a34f6d630ba
https://git.kernel.org/stable/c/aa7496d668c30ca7421b3bfdcd948ee861a13d17

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.