What’s Vulnerable › Vulnerabilities

CVE-2025-40047: io_uring/waitid: always prune wait queue entry in io_waitid_wait()

• Severity: high (CVSS 7.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-10-28 · updated 2026-10-19

Description

In the Linux kernel, the following vulnerability has been resolved: io_uring/waitid: always prune wait queue entry in io_waitid_wait() For a successful return, always remove our entry from the wait queue entry list. Previously this was skipped if a cancelation was in progress, but this can race with another invocation of the wait queue entry callback.

Affected products

• Linux kernel: 6.7 — fixed in 6.18

How to fix

Upgrade to a fixed version: Linux kernel 6.18. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/2f8229d53d984c6a05b71ac9e9583d4354e3b91f
• https://git.kernel.org/stable/c/3e2205db2f0608898d535da1964e1b376aacfdaa
• https://git.kernel.org/stable/c/696ba6032081e617564a8113a001b8d7943cb928

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