Security readout for executives and security teams
Plain-English summary
CVE-2026-5164 is a virtio-win flaw that can let a highly privileged local user crash an affected system by sending an oversized unmap request. Red Hat rates it medium. The main business impact is availability loss on affected RHEL 9 and 10 environments using virtio-win.
Executive priority
Treat as a moderate operational risk. It is not currently supported as actively exploited, but affected virtualization environments should be tracked and remediated through Red Hat guidance because successful abuse can crash systems.
Technical view
The RhelDoUnMap() function in virtio-win does not properly validate the descriptor count in an unmap request. Excessive descriptors can trigger a buffer overrun and system crash. The source description frames impact as denial of service, while the CVSS vector lists high confidentiality, integrity, and availability impact.
Likely exposure
Exposure appears limited to local users with high privileges on affected Red Hat Enterprise Linux 9 and 10 virtio-win deployments. Red Hat lists RHEL 8 as unaffected. No remote or unauthenticated attack path is described in the provided sources.
Exploitation context
No active exploitation is indicated. The CVE is not listed as KEV in the provided bundle. Public details describe a local, high-privilege input validation issue; they do not provide evidence of in-the-wild abuse.
Researcher notes
Key gaps are patch availability and exact affected build ranges in the provided bundle. The GitHub pull request may contain implementation context, but validation should rely on Red Hat’s CVE, Bugzilla, and errata data for supported environments.
Mitigation direction
- Check Red Hat’s CVE page for supported fixes or errata.
- Track the linked Bugzilla issue for vendor remediation status.
- Review the upstream GitHub pull request for engineering context.
- Limit high-privilege local access on affected systems.
- Prioritize patching affected RHEL 9 and 10 virtio-win installations when vendor guidance is available.
Validation and detection
- Inventory systems using the virtio-win package on RHEL 9 or 10.
- Confirm RHEL 8 systems are not treated as affected for this CVE.
- Compare installed package status against Red Hat’s CVE and advisory data.
- Review crash logs for unexplained virtio-win related failures.
- Verify local administrative access is restricted and monitored.
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.
CWE-120: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-5164 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
- Medium
- CVSS
- 6.7 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:H/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:H/UI:N/S:U/C:H/I:H/A:H0.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.7MediumVector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://access.redhat.com/security/cve/CVE-2026-5164CVE reference · vdb-entry, x_refsource_REDHAT
- RHBZ#2453014CVE reference · issue-tracking, x_refsource_REDHAT
- https://github.com/virtio-win/kvm-guest-drivers-windows/pull/1504CVE reference
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.
Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.