CVE-2026-52933: Linux Kernel

High severity, CVSS 7.8. EPSS: 0.1% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: io_uring/poll: fix signed comparison in io_poll_get_ownership() io_poll_get_ownership() uses a signed comparison to check whether poll_refs has reached the threshold for the slowpath: if (unlikely(atomic_read(&req->poll_refs) >= IO_POLL_REF_BIAS)) atomic_read() returns int (signed). When IO_POLL_CANCEL_FLAG (BIT(31)) is set in poll_refs, the value becomes negative in signed arithmetic, so the >= 128 comparison always evaluates to false and the slowpath is never taken. Fix this by casting the atomic_read() result to unsigned int before the comparison, so that the cancel flag is treated as a large positive value and correctly triggers the slowpath.

Affected products

• Linux Linux Kernel: from 5.15.82, before 5.16 (fixed in 5.16); from 6.0.11, before 6.1 (fixed in 6.1); from 6.1.1, before 6.1.175 (fixed in 6.1.175); from 6.2, before 6.6.140 (fixed in 6.6.140); from 6.7, before 6.12.86 (fixed in 6.12.86); from 6.13, before 6.18.27 (fixed in 6.18.27); …

Published 2026-06-24. Last modified 2026-09-08.