SB20261022479 - Use-after-free in Linux kernel io_uring
Published: October 22, 2026
Security Bulletin ID
SB20261022479
CSH Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Use-after-free (CVE-ID: CVE-2026-98858)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 5.7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to cause a denial of service through access to freed kernel memory.
The vulnerability exists due to use-after-free in the Linux kernel io_uring task_work handling when an SQPOLL thread completes the last request holding a ring alive while io_req_normal_work_add() is still accessing its context. A local user can trigger concurrent request completion and ring teardown to cause a denial of service.
Remediation
Install update from vendor's website.