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CVE-2026-45896 Linux CVE debrief

A vulnerability in the Linux kernel's Intel Discrete Graphics (DG) MTD driver could allow out-of-bounds memory access during device initialization. The flaw occurs in drivers/mtd/devices/mtd_intel_dg.c where the regions array is accessed using nregions before the variable is properly set, triggering UBSAN array-index-out-of-bounds warnings. The bug also masks memory allocation failures (ENOMEM) by silently continuing loop execution instead of properly handling errors. The fix restructures the initialization logic to set nregions before array access and properly propagate allocation failures. This affects systems using Intel discrete graphics with MTD (Memory Technology Device) support.

Vendor
Linux
Product
Unknown
CVSS
HIGH 7.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-05-27
Original CVE updated
2026-06-25
Advisory published
2026-05-27
Advisory updated
2026-06-25

Who should care

Linux system administrators running kernels with Intel Discrete Graphics MTD support; embedded systems using Intel DG storage controllers; security teams monitoring for kernel driver vulnerabilities

Technical summary

The mtd_intel_dg driver in the Linux kernel contains a logic error where the regions array is indexed using nregions before the variable is initialized. This causes undefined behavior sanitizer (UBSAN) array-index-out-of-bounds errors when accessing index 0 of an array with unknown bounds. Additionally, the initialization loop fails to properly handle ENOMEM conditions from memory allocation, silently continuing rather than propagating the error. The vulnerability is local and requires the driver to be loaded, with impact limited to potential information disclosure or denial of service through improper memory access during device probe.

Defensive priority

medium

Recommended defensive actions

  • Apply kernel updates containing the referenced stable commits when available from your Linux distribution
  • Verify Intel DG MTD driver is not loaded on critical systems if patching is delayed
  • Monitor kernel logs for UBSAN warnings related to mtd_intel_dg.c as indicators of vulnerable code paths
  • Review custom kernel builds for inclusion of the mtd_intel_dg driver module

Evidence notes

The vulnerability is confirmed by kernel commit messages resolving the UBSAN array-index-out-of-bounds error at line 750 of mtd_intel_dg.c. The fix addresses both the out-of-bounds access and improper ENOMEM handling in the region initialization loop.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-45896 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-45896

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-45896 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-45896

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/721bd22bcf45a63ebd9bd0f478ef721b45cc5383

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/779c59274d03cc5c07237a2c845dfb71cff77705

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/d58fca8513414b15387460b14a7a0a30405b9c9e

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.