SB2026102663 - Incorrect authorization in Linux kernel io_uring

Description

This security bulletin contains information about 1 vulnerability.

1) Incorrect authorization (CVE-ID: CVE-2026-99096)

CWE-ID: CWE-863 - Incorrect Authorization

CVSSv4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]

The vulnerability allows a local user to bypass task-level io_uring registration restrictions.

The vulnerability exists due to improper authorization in __io_uring_register() when processing registration operations on disabled rings with inherited task restrictions. A local user can create a ring with IORING_SETUP_R_DISABLED, issue otherwise prohibited registration opcodes, and enable the ring with IORING_REGISTER_ENABLE_RINGS to bypass the inherited restrictions.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/6da8f402e362b2f546e2efb7167fc9597aef6faf
• https://git.kernel.org/stable/c/f55c240192ded562386de843bfa067671d2731d5