Vulnerability in Linux

CVE-2026-90176

In the Linux kernel, the following vulnerability has been resolved: ksmbd: Do not skip lock checks for single-byte ranges check_lock_range() uses inclusive ranges. Its callers pass the end offset as start + length - 1, so start == end represents a valid single-byte range rather than an empty range. The start == end shortcut therefore skips mandatory byte-range lock checks for one-byte reads, writes, copychunk operations and one-byte truncate ranges. A conflicting lock covering that byte is not checked and the operation is allowed to proceed. Remove the shortcut. The truncate size == inode->i_size case is already handled by only calling check_lock_range() when the new size differs from the current file size.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.005 (42.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 43rd percentile — 42.9% 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-2026-90176: held from 0.005 to 0.005.

EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: -0.000

Affected products

References

Frequently asked questions

What is CVE-2026-90176?
CVE-2026-90176 is a high-severity vulnerability in Linux. CVSS score: 8.1/10. Published 2026-09-17.
How severe is CVE-2026-90176?
High severity. CVSS v3 base score is 8.1 out of 10.