Review reviewHigh

CVE-2025-40291

Linux

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.

CVSS
7.8
EPSS
-
- percentile
CISA KEV
Not listed
Published
2025.12.08
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability-
Technical severityCVSS 7.8

Vulnerability overview

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.

Affected product and versions

Product
Linux
Affected versions
>= 9ef4cbbcb4ac3786a1a4164507511b76b2a572c5 < 826ce37a842633efe1bb763e4b13045d74060d72, >= 9ef4cbbcb4ac3786a1a4164507511b76b2a572c5 < 146eb58629f45f8297e83d69e64d4eea4b28d972, >= 6.15
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Linux and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
Not available