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CVE Record

CVE-2025-71223: smb/server: fix refcount leak in smb2_open()

In the Linux kernel, the following vulnerability has been resolved: smb/server: fix refcount leak in smb2_open() When ksmbd_vfs_getattr() fails, the reference count of ksmbd_file must be released.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

CVE-2025-71223 is a Linux kernel SMB server issue where a file reference is not released after a specific failure path. This can leak kernel resources in systems using ksmbd. The public record does not provide CVSS, CWE, confirmed impact, or active exploitation evidence.

Executive priority

Treat this as a targeted kernel maintenance item for environments using Linux ksmbd. Prioritize exposed SMB servers and shared infrastructure, but avoid emergency assumptions because severity, CVSS, confirmed impact, and exploitation evidence are not provided.

Technical view

The fix addresses a reference count leak in ksmbd's smb2_open(). If ksmbd_vfs_getattr() fails, the ksmbd_file reference must be released. The source identifies affected Linux kernel versions and stable commits, but does not characterize exploitability beyond the leak.

Likely exposure

Exposure is most likely on Linux systems running the in-kernel SMB server, ksmbd, on affected kernel versions or builds missing the stable fix. Systems not using ksmbd appear less exposed based on the described vulnerable component.

Exploitation context

The source bundle does not report KEV listing, public exploitation, exploit code, or attacker prerequisites. The vulnerable path is in SMB open handling after an attribute lookup failure, but the available evidence is insufficient to assess practical attack reliability or impact.

Researcher notes

The record names a precise ksmbd refcount leak and stable fix references, but lacks CWE, CVSS, root-cause detail beyond the failure path, and operational impact. Validate against the exact kernel tree or distribution backport rather than version strings alone.

Mitigation direction

  • Apply Linux kernel or distribution updates that include the listed stable fixes.
  • Check vendor advisories for exact fixed package versions before deploying.
  • Disable ksmbd where the kernel SMB server is not required.
  • Restrict SMB access to trusted networks and hosts.
  • Prioritize remediation for internet-exposed or untrusted-network SMB servers.

Validation and detection

  • Inventory Linux kernel versions on systems providing SMB service.
  • Confirm whether ksmbd is enabled, loaded, or listening.
  • Compare installed kernels against vendor-fixed versions or referenced stable commits.
  • Review distribution security advisories for CVE-2025-71223 status.
  • Monitor affected hosts for unusual SMB errors or resource exhaustion symptoms.
Prepared
Confidence
medium
Sources
6

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

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CVE-2025-71223 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
3Timeline events
0ADP providers
5Source links

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux8df4bcdb0a4232192b2445256c39b787d58ef14d, c8efcc786146a951091588e5fa7e3c754850cb3c, c8efcc786146a951091588e5fa7e3c754850cb3c, c8efcc786146a951091588e5fa7e3c754850cb3c, 6.6.32unaffected
LinuxLinux6.9, 0, 6.6.124, 6.12.70, 6.18.10, 6.19affected
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.