CVE-2025-71223: Linux kernel · smb/server: fix refcount leak in smb2_open()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium.
Data as of 26 Oct 2026, 10:12 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 3% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 14 Feb 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 fix for this vulnerability is available. Users should apply the official Linux kernel updates that address this reference count leak in smb2_open().
Description
A vulnerability in the Linux kernel's SMB server component was fixed to address a reference count leak in the smb2_open() function. The issue occurred when ksmbd_vfs_getattr() failed, causing the reference count of ksmbd_file not to be released properly. This flaw could lead to resource exhaustion affecting system availability.
References
- ubuntu.com/security/CVE-2025-71223 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-71223 (opens in a new tab)
- git.kernel.org/linus/f416c556997aa56ec4384c6b6efd6a0e6ac70aa7 (opens in a new tab)
- git.kernel.org/stable/c/2456fde2b137703328f1695f60c68fe488d17e36 (opens in a new tab)
- git.kernel.org/stable/c/39ca11ff158c98fb092176f06047628c54bcf7a1 (opens in a new tab)
- git.kernel.org/stable/c/4665e52bde3b1f8f442895ce7d88fa62a43e48c4 (opens in a new tab)
- git.kernel.org/stable/c/f416c556997aa56ec4384c6b6efd6a0e6ac70aa7 (opens in a new tab)