CVE-2026-98420: Linux kernel · ksmbd: follow SMB2 session expiration semantics
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in d7fd1f98607f2cd358e583f9548bdf0173090a86 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 14:05 UTC
Rated Medium by Threat Radar's AI analysis · CVSS not yet scored by NVD
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 14% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in d7fd1f98607f2cd358e583f9548bdf0173090a86, c99ea7855124ca1428a1e59c2b4590aaef34eacf, 6.4 +3
Exploitation evidence
Disclosed: evidence found.
CVE published 14 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.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in– |
AI-suggested
A fix is available in Linux kernel versions 5.16, 6.2, 6.3, and 6.4 and later. Users should upgrade to these fixed versions to resolve the session expiration and resource exhaustion issues. No additional mitigation steps are required as the patch addresses the root cause.
Description
A vulnerability in the Linux kernel's ksmbd component mishandled SMB2 session expiration semantics, causing valid sessions to be destroyed prematurely after 10 seconds of inactivity when a client initiates another SessionSetup exchange. This behavior conflicted with Windows SMB2 session rules, leading to invalidation of tree connects and mapped drives failing with STATUS_NETWORK_NAME_DELETED. The fix aligns session expiration with credential expiration times and implements a 45-second timeout for session setup, improving compatibility and preventing memory exhaustion from unauthenticated sessions.