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.

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.

EPSS: 0.002 (6.2th percentile) — read the EPSS interpretation.

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.

Affected products

Linux — versions 9ef4cbbcb4ac3786a1a4164507511b76b2a572c5, 6.15, 0

References

416baaa9-dc9f-4396-8d5f-8c081fb06d67
416baaa9-dc9f-4396-8d5f-8c081fb06d67

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.