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CVE Record

CVE-2025-40047: io_uring/waitid: always prune wait queue entry in io_waitid_wait()

In the Linux kernel, the following vulnerability has been resolved: io_uring/waitid: always prune wait queue entry in io_waitid_wait() For a successful return, always remove our entry from the wait queue entry list. Previously this was skipped if a cancelation was in progress, but this can race with another invocation of the wait queue entry callback.

HighCVSS 7.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

A race condition in Linux io_uring process-wait handling can leave a wait-queue entry registered after a successful operation. A local, low-privileged user may be able to trigger serious confidentiality, integrity, and availability impacts. Network exposure alone is insufficient; an attacker needs local execution access.

Executive priority

Treat as a high-priority local privilege and host-compromise risk. Expedite remediation on multi-user or untrusted-workload systems; schedule ordinary accelerated patching for tightly controlled hosts. Current evidence does not justify an emergency internet-wide response.

Technical view

During io_waitid_wait(), successful completion did not always remove its wait-queue entry when cancellation was underway. A concurrent callback could race with that state. The correction always prunes the entry. The sources do not identify a CWE or establish the exact memory-corruption primitive.

Likely exposure

Prioritize Linux systems running the listed affected versions, including 6.7, 6.12.53, 6.17.3, and 6.18, where untrusted users or workloads can execute locally. The bundle also lists an ambiguous version “0”; confirm precise distribution and backport status with the vendor.

Exploitation context

The CVSS vector indicates local access, low complexity, low privileges, no user interaction, and potentially high confidentiality, integrity, and availability impact. The CVE is not listed as KEV, and the supplied sources provide no evidence of active exploitation or a public exploit.

Researcher notes

The published description supports a cancellation-versus-callback race involving wait-queue cleanup. It does not document reproducibility, affected configurations, a CWE, exploitation mechanics, or branch-by-branch fix mapping. Review the three stable commits and distribution backports before making exact exposure determinations.

Mitigation direction

  • Apply a vendor-supported kernel update containing the applicable upstream stable fix.
  • Check distribution advisories for backported fixes and precise affected package versions.
  • Prioritize shared hosts, developer systems, and platforms running untrusted local workloads.
  • Restrict unnecessary local access while remediation is pending.

Validation and detection

  • Record each system’s kernel release, package version, distribution, and architecture.
  • Compare vendor package changelogs against CVE-2025-40047 and the referenced fix commits.
  • Confirm the updated kernel is active after maintenance.
  • Recheck scanners using distribution-specific package data, not upstream version strings alone.
Prepared
Confidence
medium
Sources
5

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-2025-40047 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
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

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
3Timeline events
0ADP providers
4Source 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
7.8CVSS 3.1HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H1.85.9Linux

Vulnerability scoring details

Base CVSS 3.1 score

7.8High
CVSS 3.1 vector shape for CVE-2025-40047Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:L/AC:L/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. 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
LinuxLinuxf31ecf671ddc498f20219453395794ff2383e06b, f31ecf671ddc498f20219453395794ff2383e06b, f31ecf671ddc498f20219453395794ff2383e06bunaffected
LinuxLinux6.7, 0, 6.12.53, 6.17.3, 6.18affected
Weakness

CWE details

No CWE listed

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