Unauthenticated kernel memory corruption via stale WCID pointer
Published Jul 19, 2026 · Updated Jul 19, 2026
Use-after-free in the Linux Kernel mt7996 Wi-Fi driver from 6.15 allows remote attackers to corrupt kernel memory via MLO link teardown. mt7996_mac_sta_deinit_link() frees an mt7996_sta_link without clearing dev->mt76.wcid[idx], leaving RX and TX completion paths to dereference and write through a stale WCID pointer. An attacker must establish an 802.11be MLO session as an access point or associated client and trigger link reconfiguration, enabling kernel reads, heap corruption, a panic, or a wedged Wi-Fi subsystem.
Summary
What happened
Use-after-free in the Linux Kernel mt7996 Wi-Fi driver from 6.15 allows remote attackers to corrupt kernel memory via MLO link teardown. mt7996_mac_sta_deinit_link() frees an mt7996_sta_link without clearing dev->mt76.wcid[idx], leaving RX and TX completion paths to dereference and write through a stale WCID pointer. An attacker must establish an 802.11be MLO session as an access point or associated client and trigger link reconfiguration, enabling kernel reads, heap corruption, a panic, or a wedged Wi-Fi subsystem.
The record
- CVE
- CVE-2026-63866
- Published
- Jul 19, 2026
- Updated
- Jul 19, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- T1499
- Attack vector
- adjacent
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 19, 2026CVE publishedPublication date reported by the CVE source.
- Jul 19, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=6.15
- Affected versionversion=dd82a9e02c054052b5899872c1f32805428f6131 <455a48685feebf2d9c1656caad77f9ba1da7b06e
- Affected versionversion=dd82a9e02c054052b5899872c1f32805428f6131 <88973240dc7c976dd320b36a9e6d925c9be083ae
- Affected versionversion=dd82a9e02c054052b5899872c1f32805428f6131 <c575459b485c47615491b1fd29f04b43fdc3da56
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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