CVE-2026-68457: Linux kernel · ksmbd: use opener credentials for FSCTL mutations
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.1 Critical · fixed in 6.8.0-147.147 : patch Linux kernel as a priority.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.7% chance of exploitation in 30 days – higher than 53% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.8.0-147.147, 6.8.0-1067.70, 7.0.0-1013.13~24.04.1 +27
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 15 Aug 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 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A patch is available and should be applied to affected Linux kernel versions. The vendor advisory confirms that this issue has been fixed. Users should update to the fixed kernel versions to mitigate this vulnerability.
Description
A vulnerability in the Linux kernel's ksmbd component was resolved that involved improper use of credentials during certain FSCTL mutations (SET_SPARSE, SET_ZERO_DATA, SET_COMPRESSION). The issue caused these operations to use the current ksmbd worker credentials instead of the opener's credentials, potentially allowing unauthorized file attribute modifications. This flaw was fixed by ensuring operations run with the credentials captured when the SMB handle was opened, limiting credential scope to single-file FSCTLs.
References
- nvd.nist.gov/vuln/detail/CVE-2026-68457 (opens in a new tab)
- git.kernel.org/stable/c/1e112c47ec5dd1942e2d4ca6e8e9b712238e20c2 (opens in a new tab)
- git.kernel.org/stable/c/a8c18434e1f0d9f7989170bdb0490c0160baf065 (opens in a new tab)
- git.kernel.org/stable/c/c6394bcaf254c5baf9aff43376020be5db6d3316 (opens in a new tab)
- git.kernel.org/stable/c/cfb2c6f71d61ed807c9d7a7af331d406f1f31877 (opens in a new tab)
- git.kernel.org/stable/c/e205f3e7e8c31a47cd11efb6cf663a527177e432 (opens in a new tab)
- git.kernel.org/stable/c/fb1cae6302d58414ddf029e3f642711bd30243f7 (opens in a new tab)
- ubuntu.com/security/CVE-2026-68457 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-68457 (opens in a new tab)
- git.kernel.org/linus/c6394bcaf254c5baf9aff43376020be5db6d3316 (opens in a new tab)
- ubuntu.com/security/notices/USN-8781-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8816-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8816-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8816-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8816-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8917-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8918-1 (opens in a new tab)