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CVE Record

CVE-2026-45995: io_uring/zcrx: fix user_struct uaf

In the Linux kernel, the following vulnerability has been resolved: io_uring/zcrx: fix user_struct uaf io_free_rbuf_ring() usees a struct user_struct, which io_zcrx_ifq_free() puts it down before destroying the ring.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

CVE-2026-45995 is a Linux kernel memory-safety bug in io_uring zero-copy receive cleanup. The public record describes a use-after-free involving user_struct lifetime ordering. Business urgency depends on whether affected kernels are deployed, but the available sources do not provide CVSS, impact, or attack-vector detail.

Executive priority

Treat this as a kernel patch-management item with uncertain severity. Prioritize inventory and vendor guidance now, then schedule updates based on asset criticality, multi-tenant exposure, and distribution advisory severity once available.

Technical view

The issue is in io_uring/zcrx cleanup: io_zcrx_ifq_free() drops a user_struct before io_free_rbuf_ring() finishes using it, creating a use-after-free. The record points to upstream stable commits as fixes. No CWE, CVSS, privilege requirement, or exploit preconditions are provided.

Likely exposure

Exposure is likely limited to Linux systems running affected kernel versions or custom kernels containing the vulnerable io_uring/zcrx code before the referenced fixes. The source bundle lists Linux as affected, but does not define distributions, configurations, or reachable attack surfaces.

Exploitation context

The CVE is not listed as KEV in the supplied bundle, and no cited source claims active exploitation. The available evidence does not establish whether exploitation is local, remote, practical, or requires specific io_uring/zcrx configuration.

Researcher notes

Evidence is sparse. The confirmed technical issue is a cleanup-order use-after-free in io_uring/zcrx. Avoid assuming exploitability, attack vector, or affected configurations beyond Linux kernels carrying the vulnerable code. The referenced git.kernel.org commits are the main remediation anchors.

Mitigation direction

  • Inventory Linux kernel versions and custom kernel builds across production and development systems.
  • Apply vendor-supported kernel updates that incorporate the referenced upstream stable fixes.
  • For custom kernels, review and backport the referenced stable commits through normal kernel maintenance processes.
  • Monitor Linux distribution advisories for package-specific fixed versions and reboot requirements.

Validation and detection

  • Confirm each host kernel version against vendor advisories and the affected versions in the CVE record.
  • Check kernel package changelogs for CVE-2026-45995 or the referenced stable commit IDs.
  • For source-built kernels, verify the user_struct lifetime fix is present in the io_uring/zcrx code.
  • Document remaining systems awaiting reboot after patched kernel installation.
Prepared
Confidence
medium
Sources
4

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-2026-45995 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
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.

0CVSS vectors
3Timeline events
0ADP providers
3Source links

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
LinuxLinux5c686456a4e83ef06c74d40be05c21a0ef136684, 5c686456a4e83ef06c74d40be05c21a0ef136684unaffected
LinuxLinux6.19, 0, 7.0.4, 7.1affected
Weakness

CWE details

No CWE listed

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