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CVE Record

CVE-2026-46189: RDMA/vmw_pvrdma: Fix double free on pvrdma_alloc_ucontext() error path

In the Linux kernel, the following vulnerability has been resolved: RDMA/vmw_pvrdma: Fix double free on pvrdma_alloc_ucontext() error path Sashiko points out that pvrdma_uar_free() is already called within pvrdma_dealloc_ucontext(), so calling it before triggers a double free.

HighCVSS 7Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

A double-free bug in the Linux VMware paravirtual RDMA driver can corrupt kernel memory when user-context allocation fails. A local, low-privileged user may be able to trigger serious confidentiality, integrity, or availability consequences, although exploitation requires a specific driver path and high complexity.

Executive priority

Prioritize affected multi-user or shared-workload VMware systems where paravirtual RDMA is enabled. Treat internet-facing status alone as a poor exposure indicator because attack access is local. Patch through normal expedited kernel maintenance, with faster handling where untrusted users or tenants can access the driver.

Technical view

The pvrdma_alloc_ucontext() error path calls pvrdma_uar_free() before pvrdma_dealloc_ucontext(), which already performs that cleanup. The duplicate release creates a CWE-763 double free. CVSS 3.1 is 7.0: local access, low privileges, high attack complexity, no user interaction, unchanged scope, and high potential impact across confidentiality, integrity, and availability.

Likely exposure

Exposure is most likely on affected Linux systems using the vmw_pvrdma VMware paravirtual RDMA driver and permitting untrusted local users to reach its user-context allocation path. Systems without that driver or RDMA configuration are less likely exposed. The supplied version data is ambiguous, so validate exact distribution builds against vendor advisories.

Exploitation context

The supplied record is not in KEV and provides no evidence of active exploitation or a public exploit. Exploitation is locally initiated, requires low privileges, and is rated high complexity. Successful triggering also appears dependent on reaching a particular allocation failure path.

Researcher notes

The root cause is duplicate cleanup on an allocation error path, not ordinary successful operation. The source bundle supplies eight upstream stable commits and multiple Red Hat advisories, indicating fixes across maintained branches. Exact vulnerable-to-fixed version boundaries cannot be reconstructed confidently from the supplied version list alone.

Mitigation direction

  • Install the vendor-provided fixed kernel package applicable to the system and reboot into it.
  • Match distribution kernels against the listed Red Hat advisories or upstream stable fix commits.
  • If patching is delayed, consult the distribution vendor for supported temporary mitigations.
  • Reduce unnecessary local-account and workload access to systems exposing paravirtual RDMA.

Validation and detection

  • Inventory running kernel versions and identify systems using the vmw_pvrdma driver.
  • Determine whether VMware paravirtual RDMA is configured and accessible to untrusted local users.
  • Compare each distribution kernel build with its applicable vendor advisory and fixed package.
  • After updating, reboot and verify the running kernel is the intended fixed build.
Prepared
Confidence
high
Sources
10

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

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ATT&CK lookup starting points

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cwe · low confidence lookup

CWE-763: Exact CWE lookup

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cve · low confidence lookup

CVE-2026-46189 mapping review

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Vulnerability profileCVE Program record
Severity
High
CVSS
7 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

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.

1CVSS vectors
5Timeline events
1ADP providers
23Source links

CVSS vector scores

1 official score

We 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.

ScoreVersionSeverityVectorExploitImpactSource
7CVSS 3.1HighCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H15.9redhat-SADP

Vulnerability scoring details

Base CVSS 3.1 score

7High
CVSS 3.1 vector shape for CVE-2026-46189Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

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. ADP timelineredhat-SADP

    Reported to Red Hat.

  3. ADP timelineredhat-SADP

    Made public.

  4. CVE publishedCVE Program

    The CVE record was published.

  5. CVE updatedCVE Program

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

ADP provider summaries

redhat-SADPkernel: RDMA/vmw_pvrdma: Fix double free on pvrdma_alloc_ucontext() error path
other:Red Hat severity ratingcvssV3_1
  • 2026-05-28T00:00:00.000Z: Reported to Red Hat.
  • 2026-05-28T00:00:00.000Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux29c8d9eba550c6d73d17cc1618a9f5f2a7345aa1, 29c8d9eba550c6d73d17cc1618a9f5f2a7345aa1, 29c8d9eba550c6d73d17cc1618a9f5f2a7345aa1, 29c8d9eba550c6d73d17cc1618a9f5f2a7345aa1, 29c8d9eba550c6d73d17cc1618a9f5f2a7345aa1, 29c8d9eba550c6d73d17cc1618a9f5f2a7345aa1, 29c8d9eba550c6d73d17cc1618a9f5f2a7345aa1, 29c8d9eba550c6d73d17cc1618a9f5f2a7345aa1unaffected
LinuxLinux4.10, 0, 5.10.258, 5.15.209, 6.1.175, 6.6.140, 6.12.88, 6.18.30, 7.0.7, 7.1affected
Weakness

CWE details

CWE-763

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

CWE-763 · source CWE mapping

Release of Invalid Pointer or Reference

Release of Invalid Pointer or Reference represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

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