CVE-2026-23428: Linux kernel · ksmbd: fix use-after-free of share_conf in compound request
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 9.8 Critical · fixed in eae0dc86f71e6f3294c0cd7ffc05039258d243af : patch Linux kernel as a priority.
Data as of 26 Oct 2026, 17:30 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 26% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers can reliably automate steps 1–4 of the kill chain
- Technical impact
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-10-16.
- Patch
- Available – fixed in eae0dc86f71e6f3294c0cd7ffc05039258d243af, d08417981155883068b7260d9500ca306a03edac, c33615f995aee80657b9fdfbc4ee7f49c2bd733d +7
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 3 Apr 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
The vulnerability has been fixed in Linux kernel versions 5.15.203, 6.1.167, 6.4, and later. Users and administrators should upgrade to these or newer kernel versions to remediate the issue. No additional mitigations or workarounds are indicated in the advisory.
Description
CVE-2026-23428 is a critical use-after-free vulnerability in the Linux kernel's ksmbd SMB server component. It occurs when compound SMB2 requests reuse a tree connection object without validating its state, leading to dereferencing freed memory. This flaw can cause kernel crashes or potentially allow code execution. The issue has been fixed in Linux kernel versions 5.15.203, 6.1.167, 6.4, and later.
References
- git.kernel.org/stable/c/d08417981155883068b7260d9500ca306a03edac (opens in a new tab)
- git.kernel.org/stable/c/eae0dc86f71e6f3294c0cd7ffc05039258d243af (opens in a new tab)
- git.kernel.org/stable/c/806f13752652216db0c309392b4db3e64eeed4f2 (opens in a new tab)
- git.kernel.org/stable/c/c742b46a153d3ff95ff0825ab1950c87b9e14470 (opens in a new tab)
- git.kernel.org/stable/c/7f7468fd2a7554cea91b7d430335a3dbf01dcc09 (opens in a new tab)
- git.kernel.org/stable/c/a5929c2020ce54e1dcbd1078c0f30b8aaf73c105 (opens in a new tab)
- git.kernel.org/stable/c/c33615f995aee80657b9fdfbc4ee7f49c2bd733d (opens in a new tab)