What’s Vulnerable › Vulnerabilities

CVE-2026-98901: ksmbd: fix lease break and ack state handling

• Severity: unknown
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-23 · updated 2026-10-26

Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix lease break and ack state handling Do not skip valid lease states containing WRITE_CACHING when breaking level-II/read leases for writes and truncates. Handle lease break acknowledgments according to the SMB2 rule that the acknowledged state must be a subset of the server's break target. Apply the acknowledged state directly and keep the break pending on failed ACKs.

Affected products

• Linux kernel: before 6.6.158; before 6.12.111; before 6.18.53 — fixed in 6.12.111, 6.18.53, 6.6.158, 7.2

How to fix

Upgrade to a fixed version: Linux kernel 6.12.111, 6.18.53, 6.6.158, 7.2. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/17699905a381621c1cee5b6528feb05acedc86a4
• https://git.kernel.org/stable/c/3251ea36df5eef58aa207fbee48849d89b922ea6
• https://git.kernel.org/stable/c/5015191096db311759fef98769270336cd8b1324
• https://git.kernel.org/stable/c/fba4653a0b4dc2f6d42600abe21fb326292f70ff

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