CVE-2026-63866

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-63866", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T07:54:57.017Z", "datePublished": "2026-07-19T14:04:51.806Z", "dateUpdated": "2026-08-05T12:36:42.414Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:36:42.414Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: mt76: mt7996: Clear wcid pointer in mt7996_mac_sta_deinit_link()\n\nClear WCID pointer removing the sta link in mt7996_mac_sta_deinit_link\nroutine."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:A - The bug is in the MediaTek mt7996 WiFi driver and is reached when MLO station links are torn down via mac80211's change_sta_links callback, which a remote WiFi peer can trigger through 802.11be MLO association/reconfiguration (malicious AP to a client, or a malicious associated client to an AP/router).\nAC:L - An attacker who can complete or maintain an MLO WiFi session can deterministically trigger link removal/reconfiguration to hit mt7996_mac_sta_deinit_link(); no special memory layout or victim timing is required beyond normal MLO link churn the attacker controls.\nPR:N - Exploitation requires no local OS privileges on the victim; the attacker only needs to act as a WiFi peer (e.g., malicious AP or associated MLO client) to drive mac80211 link changes into the driver, not root/CAP_NET_ADMIN on the target host.\nUI:N - No victim user action beyond normal automatic WiFi operation is required; link add/remove is driven by the attacker's 802.11 MLO signaling once the victim device is operating as a WiFi client or AP with MLO enabled.\nS:U - Impact is confined to kernel memory corruption and privilege escalation within the same kernel/host security boundary; this is not a VM escape, sandbox escape, or cross-authority boundary bypass.\nC:H - Failing to NULL the global dev->mt76.wcid[idx] entry before mt76_wcid_mask_clear() and kfree_rcu() leaves a use-after-free; stale wcid pointers are dereferenced on RX/TX completion paths via mt76_wcid_ptr(), enabling arbitrary kernel memory reads.\nI:H - The dangling wcid pointer permits writes through subsequent TX/RX and wcid-based container_of lookups on freed mt7996_sta_link objects, giving attacker-influenced heap corruption primitives suitable for control-flow hijacking.\nA:H - Use of a freed wcid structure during packet TX completion or RX processing can cause kernel oops/panic or wedged WiFi subsystem, and UAF corruption alone satisfies High availability impact even before full exploitation."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/net/wireless/mediatek/mt76/mt7996/main.c"], "versions": [{"version": "dd82a9e02c054052b5899872c1f32805428f6131", "lessThan": "455a48685feebf2d9c1656caad77f9ba1da7b06e", "status": "affected", "versionType": "git"}, {"version": "dd82a9e02c054052b5899872c1f32805428f6131", "lessThan": "c575459b485c47615491b1fd29f04b43fdc3da56", "status": "affected", "versionType": "git"}, {"version": "dd82a9e02c054052b5899872c1f32805428f6131", "lessThan": "88973240dc7c976dd320b36a9e6d925c9be083ae", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/net/wireless/mediatek/mt76/mt7996/main.c"], "versions": [{"version": "6.15", "status": "affected"}, {"version": "0", "lessThan": "6.15", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.33", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.0.10", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.15", "versionEndExcluding": "6.18.33"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.15", "versionEndExcluding": "7.0.10"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.15", "versionEndExcluding": "7.1"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/455a48685feebf2d9c1656caad77f9ba1da7b06e"}, {"url": "https://git.kernel.org/stable/c/c575459b485c47615491b1fd29f04b43fdc3da56"}, {"url": "https://git.kernel.org/stable/c/88973240dc7c976dd320b36a9e6d925c9be083ae"}], "title": "wifi: mt76: mt7996: Clear wcid pointer in mt7996_mac_sta_deinit_link()", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["drivers/net/wireless/mediatek/mt76/mt7996/main.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "455a48685feebf2d9c1656caad77f9ba1da7b06e", "status": "affected", "version": "dd82a9e02c054052b5899872c1f32805428f6131", "versionType": "git"}, {"lessThan": "c575459b485c47615491b1fd29f04b43fdc3da56", "status": "affected", "version": "dd82a9e02c054052b5899872c1f32805428f6131", "versionType": "git"}, {"lessThan": "88973240dc7c976dd320b36a9e6d925c9be083ae", "status": "affected", "version": "dd82a9e02c054052b5899872c1f32805428f6131", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["drivers/net/wireless/mediatek/mt76/mt7996/main.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.15"}, {"lessThan": "6.15", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.33", "versionType": "semver"}, {"lessThanOrEqual": "7.0.*", "status": "unaffected", "version": "7.0.10", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.1", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "986D4552-0ECA-40C4-9708-6D088AC7A485", "versionEndExcluding": "6.18.33", "versionStartIncluding": "6.15", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "A13475D2-59BF-4716-94B5-7C1D239A2CF4", "versionEndExcluding": "7.0.10", "versionStartIncluding": "6.19", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: mt76: mt7996: Clear wcid pointer in mt7996_mac_sta_deinit_link()\n\nClear WCID pointer removing the sta link in mt7996_mac_sta_deinit_link\nroutine."}], "id": "CVE-2026-63866", "lastModified": "2026-10-26T16:51:04.883", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "ADJACENT_NETWORK", "availabilityImpact": "HIGH", "baseScore": 8.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-07-19T15:16:53.517", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/455a48685feebf2d9c1656caad77f9ba1da7b06e"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/88973240dc7c976dd320b36a9e6d925c9be083ae"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/c575459b485c47615491b1fd29f04b43fdc3da56"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "NVD-CWE-noinfo"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"bugzilla": {"description": "kernel: wifi: mt76: mt7996: Clear wcid pointer in mt7996_mac_sta_deinit_link()", "id": "2502301", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2502301"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.0", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-825", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nwifi: mt76: mt7996: Clear wcid pointer in mt7996_mac_sta_deinit_link()\nClear WCID pointer removing the sta link in mt7996_mac_sta_deinit_link\nroutine.", "A flaw was found in the Linux kernel's mt76 Wi-Fi driver for mt7996 devices. This vulnerability occurs when the `mt7996_mac_sta_deinit_link()` routine fails to properly clear a Wireless Client ID (WCID) pointer when removing a station link. This improper handling of the WCID pointer may lead to a resource management issue, potentially causing system instability or a denial of service."], "name": "CVE-2026-63866", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-07-19T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-63866\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-63866\nhttps://lore.kernel.org/linux-cve-announce/2026071934-CVE-2026-63866-d861@gregkh/T"], "threat_severity": "Important"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[dd82a9e02c054052b5899872c1f32805428f6131,455a48685feebf2d9c1656caad77f9ba1da7b06e)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[dd82a9e02c054052b5899872c1f32805428f6131,c575459b485c47615491b1fd29f04b43fdc3da56)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[dd82a9e02c054052b5899872c1f32805428f6131,88973240dc7c976dd320b36a9e6d925c9be083ae)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "6.15"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,6.15)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.33,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.0.10,7.1.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.1,*)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-07-22T04:45:02.577015+00:00", "updated": "2026-10-26T19:15:14.896602+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}