VulnerabilityPublished 23 Oct 2026

CVE-2026-98897: Linux kernel · ksmbd: don't hold ci->m_lock while waiting for a lease break ack

Source GCVE Database

Authoritative record:CVE-2026-98897· Medium

Not known to be exploited · fixed in 868c9038ffd4af39766d087f68c8f543a3f66635 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 17:16 UTC

Severity

Medium

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 868c9038ffd4af39766d087f68c8f543a3f66635, 27a9bc968d4ae809a3f5ca2f2b136856ee613cb4, 6.7

Exploitation evidence

Disclosed: evidence found.
CVE published 23 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-83j5-g9m2-9mf4

What to do

Upgrade Linux kernel to 868c9038ffd4af39766d087f68c8f543a3f66635, 27a9bc968d4ae809a3f5ca2f2b136856ee613cb4 or 6.7.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected >=6.6.35 <6.7	Fixed in 868c9038ffd4af39766d087f68c8f543a3f66635 27a9bc968d4ae809a3f5ca2f2b136856ee613cb4 6.7
LinuxLinux	Affected =6.9	Fixed in–

AI-suggested

A fix has been implemented in the Linux kernel to resolve this issue by changing the locking strategy during lease break acknowledgment waits. Users should update to the fixed kernel version once available. No additional mitigation is indicated or required beyond applying the official fix.

Description

A vulnerability in the Linux kernel's ksmbd component related to lease break handling has been resolved. The issue involved holding a read lock (ci->m_lock) while waiting for a lease break acknowledgment, causing a deadlock scenario that delayed lease break resolution by up to 35 seconds. This resulted in significantly increased operation times in tests with leases enabled. The fix changes the locking strategy to avoid holding the lock during the wait, preventing the deadlock.

Impact

The vulnerability caused a deadlock condition in the ksmbd lease break handling, resulting in lease break acknowledgments being delayed by up to 35 seconds. This significantly increased operation times in affected scenarios, such as the xfstests generic/001 test, which took approximately 78 seconds with leases enabled compared to about 4 seconds with oplocks only. There is no indication of direct security compromise or exploitation in the wild.

References

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