CVE-2026-90176

linux: In the Linux kernel, the following vulnerability has been resolved: ksmbd: Do not skip lock checks for single-byte r...

CVE-2026-90176 is fixed in 2 products on 1 platform, first by DEBIAN-CVE-2026-90176, released September 23, 2026. It is not reported as exploited. Patch Radar priority: High.

High
CVSS
8.1
high
Exploitation
None reported
No vendor assessment
CISA KEV
Not listed
Not in the Known Exploited Vulnerabilities catalog
EPSS
0.0050
43rd percentile

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.

Where it's fixed

ProductFixed inFixReleased
Linux
linux · Debian 12.15 (bookworm) 6.1.190-1 DEBIAN-CVE-2026-90176 Sep 23, 2026
linux · Debian 13.5 (trixie) 6.12.111-1 DEBIAN-CVE-2026-90176 Sep 23, 2026
linux · Debian 14 7.2.6-1 DEBIAN-CVE-2026-90176 Sep 23, 2026
linux-6.12 · Debian 12.15 (bookworm) 6.12.111-1~deb12u1 DEBIAN-CVE-2026-90176 Sep 23, 2026

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