CVE-2026-81009io_uring/query: cap user size passed to copy_struct_to_user
Updated under an hour ago ()
Does this affect you?
It affects Linux. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
Do this next
Free account, 1 product
In the Linux kernel, the following vulnerability has been resolved: io_uring/query: cap user size passed to copy_struct_to_user io_handle_query_entry() clamps hdr.size for the inbound copy_from_user() but keeps the original user value as usize. copy_struct_to_user() uses that usize and, when it is larger than the kernel result, clear_user()s the trailing bytes. As hdr.size is a __u32, a query can request nearly 4 GiB of zeroing, including on the error path where res_size stays 0. The interface is reachable without a ring via IORING_REGISTER_QUERY. Reject sizes larger than PAGE_SIZE, as recommended for copy_struct_* interfaces.
- CVSS
- Not yet scored
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Received
- Record last updated
- Sep 11, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from c265ae75f900cea4e415230a77b5d152377627dd before 417e02f7b6051765b91cf1289071882eebd172e0; from c265ae75f900cea4e415230a77b5d152377627dd before 2b8ad4981ecedb14c1fdd811ab977010b23933e6; from c265ae75f900cea4e415230a77b5d152377627dd before ba77efee1b95b4ad7559b1cdbe7cd7fa36dca95b | CNA record |
References
- https://git.kernel.org/stable/c/417e02f7b6051765b91cf1289071882eebd172e0
- https://git.kernel.org/stable/c/2b8ad4981ecedb14c1fdd811ab977010b23933e6
- https://git.kernel.org/stable/c/ba77efee1b95b4ad7559b1cdbe7cd7fa36dca95b
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.