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CVE Record

CVE-2026-43281: mailbox: Prevent out-of-bounds access in fw_mbox_index_xlate()

In the Linux kernel, the following vulnerability has been resolved: mailbox: Prevent out-of-bounds access in fw_mbox_index_xlate() Although it is guided that `#mbox-cells` must be at least 1, there are many instances of `#mbox-cells = <0>;` in the device tree. If that is the case and the corresponding mailbox controller does not provide `fw_xlate` and of_xlate` function pointers, `fw_mbox_index_xlate()` will be used by default and out-of-bounds accesses could occur due to lack of bounds check in that function.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

This is a Linux kernel memory-safety bug in mailbox handling. Certain device-tree configurations can cause the kernel to read outside expected bounds when translating mailbox indexes. The public record does not provide CVSS, confirmed impact, or exploit evidence, so urgency depends on whether affected kernel builds and device-tree patterns exist in your fleet.

Executive priority

Handle through normal kernel vulnerability management unless asset review finds exposed embedded or appliance Linux systems. There is no cited active exploitation, but kernel memory-safety issues can carry operational risk when present in supported production platforms.

Technical view

The flaw is in fw_mbox_index_xlate(), used as a default when mailbox controllers lack fw_xlate and of_xlate callbacks. Device trees with #mbox-cells = <0> can trigger out-of-bounds access because the function lacked a bounds check. Linux stable commits are referenced as fixes.

Likely exposure

Exposure appears limited to Linux systems running affected kernel versions with device-tree mailbox configurations using #mbox-cells = <0> and controllers without custom translation callbacks. This is more likely relevant to embedded, appliance, or SoC-based Linux deployments than generic userland-only workloads.

Exploitation context

The source bundle says KEV is false and provides no evidence of active exploitation, proof-of-concept use, remote reachability, or attacker prerequisites. Treat exploitability as unproven from available public evidence.

Researcher notes

Key unknowns are impact, attacker control over the triggering path, and reachable device-tree configurations. The record identifies a bounds-check issue and stable kernel fixes, but does not classify the bug with CVSS or CWE. Validate against actual device-tree and mailbox-controller implementations.

Mitigation direction

  • Apply a Linux kernel update containing the referenced stable fixes.
  • Check downstream vendor or distribution advisories for packaged fixed kernels.
  • Prioritize embedded and appliance Linux systems with custom device trees.
  • Review device-tree mailbox definitions for #mbox-cells = <0>.
  • Track CVE-2026-43281 until CVSS and vendor impact statements mature.

Validation and detection

  • Inventory deployed Linux kernel versions against vendor-fixed releases.
  • Confirm whether affected systems use device-tree mailbox controllers.
  • Review kernel source or changelog for the referenced stable commit IDs.
  • Ask appliance vendors whether their builds include this mailbox fix.
  • Document systems where the triggering device-tree pattern is absent.
Prepared
Confidence
medium
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

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-2026-43281 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
9Source 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
LinuxLinux2b6d83e2b8b7de82331a6a1dcd64b51020a6031c, 2b6d83e2b8b7de82331a6a1dcd64b51020a6031c, 2b6d83e2b8b7de82331a6a1dcd64b51020a6031c, 2b6d83e2b8b7de82331a6a1dcd64b51020a6031c, 2b6d83e2b8b7de82331a6a1dcd64b51020a6031c, 2b6d83e2b8b7de82331a6a1dcd64b51020a6031c, 2b6d83e2b8b7de82331a6a1dcd64b51020a6031c, 2b6d83e2b8b7de82331a6a1dcd64b51020a6031cunaffected
LinuxLinux3.18, 0, 5.10.258, 5.15.209, 6.1.167, 6.6.130, 6.12.77, 6.18.16, 6.19.6, 7.0affected
Weakness

CWE details

No CWE listed

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