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CVE Record

CVE-2025-40066: wifi: mt76: mt7996: Check phy before init msta_link in mt7996_mac_sta_add_links()

In the Linux kernel, the following vulnerability has been resolved: wifi: mt76: mt7996: Check phy before init msta_link in mt7996_mac_sta_add_links() In order to avoid a possible NULL pointer dereference in mt7996_mac_sta_init_link routine, move the phy pointer check before running mt7996_mac_sta_init_link() in mt7996_mac_sta_add_links routine.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2025-40066 is a Linux kernel Wi-Fi driver flaw that can cause a NULL pointer dereference in the MediaTek mt7996 driver path. The public record does not provide a CVSS score or confirmed exploitation. Business urgency is highest for systems using affected Linux kernels with mt76/mt7996 Wi-Fi hardware or driver support.

Executive priority

Prioritize routine-to-expedited remediation for Linux endpoints, appliances, or embedded systems using MediaTek mt7996 Wi-Fi. This is not currently supported as internet-wide emergency risk, but kernel crashes on Wi-Fi infrastructure or critical devices could cause operational disruption.

Technical view

The issue is in wifi/mt76/mt7996. In mt7996_mac_sta_add_links(), the code could call mt7996_mac_sta_init_link() before validating the phy pointer, allowing a possible NULL pointer dereference. The fix moves the phy check before initializing msta_link. Linux stable commit references are provided as remediation evidence.

Likely exposure

Exposure appears limited to Linux systems running affected kernel versions with the mt76 mt7996 Wi-Fi driver path present or in use. Servers without this hardware or driver are less likely exposed. The provided affected-version data is incomplete and should be verified against distribution kernel advisories.

Exploitation context

No CISA KEV listing or cited source confirms active exploitation. The public sources do not describe attacker prerequisites, remote reachability, or a proof of concept. Treat this primarily as a kernel availability-risk issue until vendor advisories provide more detail.

Researcher notes

The record lacks CVSS, CWE, detailed reachability, and triggering conditions. Analysis should focus on the referenced kernel commits, affected version mapping, and downstream distro backports. Avoid assuming exploitability beyond the documented NULL pointer dereference.

Mitigation direction

  • Apply a vendor or Linux stable kernel update containing the referenced fixes.
  • Check distribution advisories for backported patches matching CVE-2025-40066.
  • If patching is delayed, assess disabling unused mt7996 Wi-Fi hardware or driver support.
  • Prioritize systems where mt7996 Wi-Fi is enabled or business-critical.

Validation and detection

  • Inventory Linux kernel versions across affected assets.
  • Identify systems with mt76 or mt7996 driver support loaded or configured.
  • Confirm installed kernels include the referenced stable fix commits or distributor backports.
  • Review crash logs for NULL pointer dereference events in mt7996 Wi-Fi code.
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

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CVE-2025-40066 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
LinuxLinuxdd82a9e02c054052b5899872c1f32805428f6131, dd82a9e02c054052b5899872c1f32805428f6131unaffected
LinuxLinux6.15, 0, 6.17.3, 6.18affected
Weakness

CWE details

No CWE listed

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