Security readout for executives and security teams
Plain-English summary
A flaw in Linux’s in-kernel SMB server, ksmbd, can access memory after it has been released when processing an oplock or lease-break acknowledgement error. A network user with limited privileges may be able to crash the system or compromise confidentiality and integrity. The supplied evidence does not establish successful code execution.
Executive priority
Prioritize expedited remediation for internet-facing, broadly reachable, or business-critical ksmbd servers. Treat disabled or unreachable ksmbd systems as lower immediate exposure after verification. Because the maximum stated impacts are high, track remediation to completion even though active exploitation is not established.
Technical view
When ksmbd_iov_pin_rsp returns an error, the affected path may access opinfo->state after release and call opinfo_put and ksmbd_fd_put twice. This creates a potential use-after-free during oplock or lease-break acknowledgement handling. CVSS 3.1 is 8.8: network reachable, low complexity, low privileges, no user interaction, with high impact ratings.
Likely exposure
Exposure is concentrated on Linux systems running an affected kernel with ksmbd enabled and reachable by SMB clients. Systems not using ksmbd are unlikely to expose this path. The bundled version data does not clearly express every distribution-specific fixed boundary, so kernel package status must be confirmed with the applicable vendor.
Exploitation context
The CVE is not identified as being in CISA KEV in the supplied bundle. No supplied source documents active exploitation or a public proof of concept. The CVSS vector indicates a low-privileged network attacker, but practical reliability and outcomes beyond a potential use-after-free are not established here.
Researcher notes
The described defect is an error-path lifetime-management failure involving opinfo state access and duplicate reference releases after ksmbd_iov_pin_rsp fails. The sources support potential use-after-free, but do not establish exploit primitives, reliable remote code execution, affected configuration nuances, or active abuse. Match vendor kernels to the relevant stable commits rather than relying only on release numbers.
Mitigation direction
- Install a vendor-supported kernel containing the applicable Linux stable fix.
- Disable ksmbd where in-kernel SMB service is unnecessary.
- Restrict SMB access to trusted networks and authenticated users while patching.
- Check distribution security guidance for package-specific fixed versions.
Validation and detection
- Determine whether ksmbd is enabled or loaded on each system.
- Identify the running kernel and distribution package version.
- Confirm the package includes the applicable referenced stable-kernel fix.
- Verify SMB is not exposed beyond explicitly authorized networks.
- Review kernel logs for ksmbd crashes or memory-safety warnings.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
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
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CVE-2025-38437 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H2.85.9LinuxVulnerability scoring details
Base CVSS 3.1 score
8.8HighVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://git.kernel.org/stable/c/e38ec88a2b42c494601b1213816d75f0b54d9bf0CVE reference, Linux
- https://git.kernel.org/stable/c/97c355989928a5f60b228ef5266c1be67a46cdf9CVE reference, Linux
- https://git.kernel.org/stable/c/815f1161d6dbc4c54ccf94b7d3fdeab34b4d7477CVE reference, Linux
- https://git.kernel.org/stable/c/8106adc21a2270c16abf69cd74ccd7c79c6e7acdCVE reference, Linux
- https://git.kernel.org/stable/c/50f930db22365738d9387c974416f38a06e8057eCVE reference, Linux
- https://lists.debian.org/debian-lts-announce/2025/10/msg00008.htmlCVE reference, CVE
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.