CVE-2025-68817: Linux kernel · ksmbd: fix use-after-free in ksmbd_tree_connect_put under concurrency
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.8 Critical · fixed in 5.15.0-1105.112~20.04.1 : patch Linux kernel as a priority.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 38% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1105.112~20.04.1, 5.15.0-1110.119~20.04.1, 5.15.0-1106.115~20.04.1 +76
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 13 Jan 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 |
|---|---|---|
Ubuntu 25.10linuxpkg:deb/ubuntu/linux?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free in ksmbd_tree_connect_put under concurrency Under high concurrency, A tree-connection object (tcon) is freed on a disconnect path while another path still holds a reference and later executes *_put()/write on it.
References
- ubuntu.com/security/CVE-2025-68817 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-68817 (opens in a new tab)
- git.kernel.org/linus/b39a1833cc4a2755b02603eec3a71a85e9dff926 (opens in a new tab)
- git.kernel.org/stable/c/063cbbc6f595ea36ad146e1b7d2af820894beb21 (opens in a new tab)
- git.kernel.org/stable/c/21a3d01fc6db5129f81edb0ab7cb94fd758bcbea (opens in a new tab)
- git.kernel.org/stable/c/b39a1833cc4a2755b02603eec3a71a85e9dff926 (opens in a new tab)
- git.kernel.org/stable/c/d092de8a26c952379ded8e6b0bda31d89befac1a (opens in a new tab)
- git.kernel.org/stable/c/d64977495e44855f2b28d8ce56107c963a7a50e4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8162-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8177-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8179-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8180-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8177-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8183-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8184-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8179-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8185-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8180-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8186-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8187-1 (opens in a new tab)