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CVE Record

CVE-2026-46054: selinux: fix overlayfs mmap() and mprotect() access checks

In the Linux kernel, the following vulnerability has been resolved: selinux: fix overlayfs mmap() and mprotect() access checks The existing SELinux security model for overlayfs is to allow access if the current task is able to access the top level file (the "user" file) and the mounter's credentials are sufficient to access the lower level file (the "backing" file). Unfortunately, the current code does not properly enforce these access controls for both mmap() and mprotect() operations on overlayfs filesystems. This patch makes use of the newly created security_mmap_backing_file() LSM hook to provide the missing backing file enforcement for mmap() operations, and leverages the backing file API and new LSM blob to provide the necessary information to properly enforce the mprotect() access controls.

HighCVSS 7.1Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

This Linux kernel flaw weakens SELinux protection on overlayfs files. A local low-privileged user or workload may access or change data that SELinux policy should have blocked. Business urgency is highest for multi-user Linux systems and container hosts using overlayfs with SELinux.

Executive priority

Treat as high priority for Linux container hosts, shared systems, and regulated environments relying on SELinux boundaries. No active exploitation is cited, but the impact is serious enough to patch during the next urgent kernel maintenance window.

Technical view

SELinux did not consistently enforce backing-file access checks for overlayfs mmap() and mprotect() operations. The kernel fix adds security_mmap_backing_file() enforcement and backing-file metadata needed for mprotect() decisions. The CVSS 3.1 score is 7.1, with high confidentiality and integrity impact, local attack vector, and low privileges required.

Likely exposure

Linux systems using SELinux with overlayfs are the relevant exposure. Risk is most meaningful where untrusted local users, tenants, or application workloads can interact with overlayfs-backed files. The bundle names Linux as affected and includes Red Hat advisories, but it does not provide a full distribution matrix.

Exploitation context

The source bundle does not show CISA KEV listing or cited active exploitation. Exploitation is local, requires low privileges, and needs an overlayfs/SELinux context where missing backing-file checks matter. No remote unauthenticated path is identified in the provided sources.

Researcher notes

Focus validation on SELinux policy enforcement for overlayfs mmap() and mprotect() paths. The fix introduces backing-file enforcement through a new LSM hook and related backing-file metadata. Avoid assuming exploitability on systems without SELinux, overlayfs, or local attacker access.

Mitigation direction

  • Apply vendor kernel updates or Red Hat advisories where applicable.
  • Prioritize hosts using SELinux and overlayfs, including container infrastructure.
  • Reboot or live-patch as required by your kernel vendor.
  • Check vendor guidance for distribution-specific fixed kernel versions.
  • Reduce untrusted local access until patched where practical.

Validation and detection

  • Inventory kernel versions on SELinux-enabled Linux systems.
  • Identify systems mounting or relying on overlayfs.
  • Check installed kernel packages against vendor advisories.
  • Confirm the relevant stable kernel fix is present.
  • Verify post-update reboot or live-patch activation completed.
Prepared
Confidence
high
Sources
12

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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CVE-2026-46054 mapping review

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Vulnerability profileCVE Program record
Severity
High
CVSS
7.1 (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:N

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.

2CVSS vectors
5Timeline events
1ADP providers
13Source links

CVSS vector scores

2 official scores

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
7.1CVSS 3.1HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N1.85.2Linux
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

7.1High
CVSS 3.1 vector shape for CVE-2026-46054Attack 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:N

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: selinux: fix overlayfs mmap() and mprotect() access checks
other:Red Hat severity ratingcvssV3_1
  • 2026-05-27T00:00:00.000Z: Reported to Red Hat.
  • 2026-05-27T00:00:00.000Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux2f502839e85ab265f03f25f30d6463154aee5473, 2f502839e85ab265f03f25f30d6463154aee5473, 2f502839e85ab265f03f25f30d6463154aee5473, 2f502839e85ab265f03f25f30d6463154aee5473, 2f502839e85ab265f03f25f30d6463154aee5473unaffected
LinuxLinux4.19, 0, 6.6.144, 6.12.95, 6.18.38, 7.0.4, 7.1affected
Weakness

CWE details

CWE-280

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

CWE-280 · source CWE mapping

Improper Handling of Insufficient Permissions or Privileges

Improper Handling of Insufficient Permissions or Privileges represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

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