CVE-2026-52933
What it is
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.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 0.1% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.1% in the next 30 days (EPSS).
- Severity: 7.8 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.1% · EPSS, next 30 days
- Weakness
- CWE-835
- Record status
- Modified
Affected
- Linux Kernel < 5.16
- Linux Kernel < 6.1
- Linux Kernel < 6.1.175
- Linux Kernel < 6.6.140
- Linux Kernel < 6.12.86
- Linux Kernel < 6.18.27
- Linux Kernel < 7.0.4
- Linux Kernel 6.1
Attack profile CVSS 3.1 · 7.8
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-52933.md and follow it. Check whether this project is affected by CVE-2026-52933. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/326941b22806cbf2df1fbfe902b7908b368cce42
- https://git.kernel.org/stable/c/81bf96b0abbfa4cd47ea32e12596aed3855fb2f3
- https://git.kernel.org/stable/c/c6d191164dc81838d8dbf452a6000f68c558d1ae
- https://git.kernel.org/stable/c/cf522703d4f194991615763697ae25a3f9539763
- https://git.kernel.org/stable/c/ea0697129807d718037f618221037aa0660ee3c5
- https://git.kernel.org/stable/c/fc47043f3d9af3efa407665b47f8378ec691ba18
References
- https://git.kernel.org/stable/c/326941b22806cbf2df1fbfe902b7908b368cce42
- https://git.kernel.org/stable/c/81bf96b0abbfa4cd47ea32e12596aed3855fb2f3
- https://git.kernel.org/stable/c/c6d191164dc81838d8dbf452a6000f68c558d1ae
- https://git.kernel.org/stable/c/cf522703d4f194991615763697ae25a3f9539763
- https://git.kernel.org/stable/c/ea0697129807d718037f618221037aa0660ee3c5
- https://git.kernel.org/stable/c/fc47043f3d9af3efa407665b47f8378ec691ba18
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
- https://cert-portal.siemens.com/productcert/html/ssa-457936.html