CVE-2026-63866 (GCVE-0-2026-63866)

Vulnerability from cvelistv5 – Published: 2026-07-19 14:04 – Updated: 2026-08-05 12:36
VLAI
Title
wifi: mt76: mt7996: Clear wcid pointer in mt7996_mac_sta_deinit_link()
Summary
In the Linux kernel, the following vulnerability has been resolved: wifi: mt76: mt7996: Clear wcid pointer in mt7996_mac_sta_deinit_link() Clear WCID pointer removing the sta link in mt7996_mac_sta_deinit_link routine.
Severity
8.8 (High)
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: dd82a9e02c054052b5899872c1f32805428f6131 , < 455a48685feebf2d9c1656caad77f9ba1da7b06e (git)
Affected: dd82a9e02c054052b5899872c1f32805428f6131 , < c575459b485c47615491b1fd29f04b43fdc3da56 (git)
Affected: dd82a9e02c054052b5899872c1f32805428f6131 , < 88973240dc7c976dd320b36a9e6d925c9be083ae (git)
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Linux Linux Affected: 6.15
Unaffected: 0 , < 6.15 (semver)
Unaffected: 6.18.33 , ≤ 6.18.* (semver)
Unaffected: 7.0.10 , ≤ 7.0.* (semver)
Unaffected: 7.1 , ≤ * (original_commit_for_fix)
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "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"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.33",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0.10",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "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": {
            "baseScore": 8.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "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\u0027s 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\u0027s 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-\u003emt76.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."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T12:36:42.414Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "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"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-63866",
    "datePublished": "2026-07-19T14:04:51.806Z",
    "dateReserved": "2026-07-19T07:54:57.017Z",
    "dateUpdated": "2026-08-05T12:36:42.414Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-63866",
      "date": "2026-09-21",
      "epss": "0.00245",
      "percentile": "0.15989"
    },
    "nvd": {
      "cve": {
        "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"
          }
        ],
        "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": "2026-07-27T17:44:23.777",
        "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",
            "url": "https://git.kernel.org/stable/c/455a48685feebf2d9c1656caad77f9ba1da7b06e"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/88973240dc7c976dd320b36a9e6d925c9be083ae"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/c575459b485c47615491b1fd29f04b43fdc3da56"
          }
        ],
        "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "vulnStatus": "Awaiting Analysis"
      }
    },
    "redhat_vex": {
      "aggregate_severity": "Important",
      "current_release_date": "2026-07-22T03:08:21+00:00",
      "cve": "CVE-2026-63866",
      "id": "CVE-2026-63866",
      "initial_release_date": "2026-07-19T00:00:00+00:00",
      "product_status:known_not_affected": "274",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: wifi: mt76: mt7996: Clear wcid pointer in mt7996_mac_sta_deinit_link()",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-63866.json",
      "version": "3"
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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