CVE-2026-31409: Linux kernel · ksmbd: unset conn->binding on failed binding request
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 8.8 High · patch available : patch Linux kernel soon.
Data as of 26 Oct 2026, 12:55 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 39% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 6 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
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linuxpkg:deb/ubuntu/linux@6.17.0-40.40?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws@6.17.0-1019.19?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure@6.17.0-1020.20?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde@6.17.0-1017.17?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp@6.17.0-1020.22?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle@6.17.0-1018.18?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.
AI-suggested
A patch is available and should be applied promptly. The vendor advisory from Ubuntu confirms that this issue has been fixed in updated Linux kernel packages. Users should upgrade to the fixed kernel versions to remediate this vulnerability.
Description
A vulnerability in the Linux kernel's ksmbd component was fixed where a failed multichannel SMB2_SESSION_SETUP binding request left the connection in an incorrect binding state. This flaw caused subsequent session lookups to fallback improperly, potentially leading to security issues. The issue has been addressed by clearing the binding state on error paths. The vulnerability affects specific Linux kernel versions and has a high CVSS score of 8.8. A patch is available as part of security updates.
References
- ubuntu.com/security/CVE-2026-31409 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-31409 (opens in a new tab)
- git.kernel.org/linus/282343cf8a4a5a3603b1cb0e17a7083e4a593b03 (opens in a new tab)
- git.kernel.org/stable/c/282343cf8a4a5a3603b1cb0e17a7083e4a593b03 (opens in a new tab)
- git.kernel.org/stable/c/6260fc85ed1298a71d24a75d01f8b2e56d489a60 (opens in a new tab)
- git.kernel.org/stable/c/6ebef4a220a1ebe345de899ebb9ae394206fe921 (opens in a new tab)
- git.kernel.org/stable/c/89afe5e2dbea6e9d8e5f11324149d06fa3a4efca (opens in a new tab)
- git.kernel.org/stable/c/9feb2d1bf86d9e5e66b8565f37f8d3a7d281a772 (opens in a new tab)
- git.kernel.org/stable/c/d073870dab8f6dadced81d13d273ff0b21cb7f4e (opens in a new tab)
- ubuntu.com/security/notices/USN-8567-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8574-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8575-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8576-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8574-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8595-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8596-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8575-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8576-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8597-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8595-2 (opens in a new tab)