Security readout for executives and security teams
Plain-English summary
CVE-2025-40051 is a high-severity Linux kernel flaw in vhost vringh handling. A local, low-privileged user may trigger incorrect handling of incomplete data copies, potentially compromising confidentiality, integrity, and availability. Exposure depends on the running kernel and whether the affected functionality is reachable.
Executive priority
Treat as a high-priority kernel update, especially on multi-user or virtualization infrastructure. The vulnerability requires local low-privileged access, reducing internet-scale exposure, but the stated impact spans full confidentiality, integrity, and availability. Patch promptly after vendor applicability and operational testing.
Technical view
The vringh code incorrectly evaluated copy_from_iter and copy_to_iter results as potentially negative. These functions return copied lengths, so the correct condition is whether the copied length equals the requested length. The supplied kernel commits change that validation. The bundle does not describe the precise failure mode or demonstrate exploitability.
Likely exposure
Risk is primarily to Linux systems running an affected kernel where vhost vringh functionality is present and reachable by a local low-privileged user. The supplied affected-version data is ambiguous and includes versions from 6.0 through 6.18; confirm exact distribution kernel applicability with vendor guidance.
Exploitation context
The CVSS vector indicates local access, low complexity, low privileges, and no user interaction, with potentially high confidentiality, integrity, and availability impact. The bundle marks this CVE as absent from KEV and provides no evidence of active exploitation or a public exploit.
Researcher notes
The core defect is a return-value semantic mismatch: copied byte counts must be compared with requested lengths. The source bundle supplies five stable-kernel fix commits but no CWE, crash trace, proof of concept, affected configuration details, or exploitation evidence. Version boundaries should not be inferred solely from the flattened version list.
Mitigation direction
- Apply the appropriate Linux distribution kernel security update containing the referenced upstream fix.
- Check vendor advisories to map distribution kernel builds to the supplied affected versions and commits.
- Restrict untrusted local access until affected systems are updated.
- Prioritize shared virtualization hosts and other systems where vhost functionality is operationally important.
Validation and detection
- Inventory running kernel versions across Linux systems.
- Determine whether each kernel contains an applicable referenced fix commit or vendor backport.
- Confirm whether vhost vringh functionality is configured, loaded, or reachable by local users.
- Verify updated systems are running the new kernel after installation and reboot.
- Monitor vendor advisories for clarified affected-version boundaries and exploitation information.
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-2025-40051 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
- 7.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/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:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H1.85.9LinuxVulnerability scoring details
Base CVSS 3.1 score
7.8HighVector: CVSS:3.1/AV:L/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.
Source materials
- CVE List V5 sourceCVE List V5
- https://git.kernel.org/stable/c/db042925a5ab7a550b710addeadbf6f72e3a8a4bCVE reference, Linux
- https://git.kernel.org/stable/c/78dc7362662fedaa1928fb8e4f27401c8322905dCVE reference, Linux
- https://git.kernel.org/stable/c/baa37b1c7e29546f79c39bef0d18c4edc9f39bb1CVE reference, Linux
- https://git.kernel.org/stable/c/cfa0654402c06d086201a9ff167eb95da5844fc3CVE reference, Linux
- https://git.kernel.org/stable/c/82a8d0fda55b35361ee7f35b54fa2b66d7847d2bCVE reference, Linux
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.