Vulnerability in Linux

CVE-2025-40291

In the Linux kernel, the following vulnerability has been resolved: io_uring: fix regbuf vector size truncation There is a report of io_estimate_bvec_size() truncating the calculated number of segments that leads to corruption issues. Check it doesn't overflow "int"s used later. Rough but simple, can be improved on top.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.001 (3.1th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 3rd percentile — 3.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-40291: held from 0.001 to 0.001.

EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: +0.000

Affected products

  • Linux — versions 9ef4cbbcb4ac3786a1a4164507511b76b2a572c5, 6.15, 0

References

Frequently asked questions

What is CVE-2025-40291?
CVE-2025-40291 is a high-severity vulnerability in Linux. CVSS score: 7.8/10. Published 2025-12-08.
How severe is CVE-2025-40291?
High severity. CVSS v3 base score is 7.8 out of 10.