← Back to CVE Explorer

CVE-2026-52937

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: tap: fix stack info leak in tap_ioctl() SIOCGIFHWADDR In the SIOCGIFHWADDR path, tap_ioctl() copies 16 bytes of an uninitialised on-stack struct sockaddr_storage to userspace via ifr_hwaddr, but netif_get_mac_address() only writes sa_family and dev->addr_len (6 for Ethernet) bytes, leaving sa_data[6..13] uninitialised. Those 8 trailing bytes leak kernel stack contents; SIOCGIFHWADDR on a macvtap chardev returns kernel .text and direct-map pointers, defeating KASLR. Initialise ss at declaration.

Severity
MEDIUM
CVSS score
5.5 (v3.1)
Vulnerability status
Modified
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-06-24 08:16:23.980000
Last modified
2026-10-30 13:19:04.617000
View original CVE JSON
{
  "id": "CVE-2026-52937",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-06-24T08:16:23.980",
  "lastModified": "2026-10-30T13:19:04.617",
  "vulnStatus": "Modified",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntap: fix stack info leak in tap_ioctl() SIOCGIFHWADDR\n\nIn the SIOCGIFHWADDR path, tap_ioctl() copies 16 bytes of an\nuninitialised on-stack struct sockaddr_storage to userspace via\nifr_hwaddr, but netif_get_mac_address() only writes sa_family and\ndev->addr_len (6 for Ethernet) bytes, leaving sa_data[6..13] uninitialised.\n\nThose 8 trailing bytes leak kernel stack contents; SIOCGIFHWADDR on a\nmacvtap chardev returns kernel .text and direct-map pointers, defeating\nKASLR.\n\nInitialise ss at declaration."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "drivers/net/tap.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "3b23a32a63219f51a5298bc55a65ecee866e79d0",
              "lessThan": "4b6dcfe0e3dfffd8057a4fc99b3f096c45709905",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "3b23a32a63219f51a5298bc55a65ecee866e79d0",
              "lessThan": "37d028a473b0826ad5970b52b791db4a29a23627",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "3b23a32a63219f51a5298bc55a65ecee866e79d0",
              "lessThan": "8197905d97099d8b1e3883112bbb497abd20f9f0",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "3b23a32a63219f51a5298bc55a65ecee866e79d0",
              "lessThan": "719007c3492f0f1f9e9cdbed8ac45ba45bb13eeb",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "3b23a32a63219f51a5298bc55a65ecee866e79d0",
              "lessThan": "05305e832be7b9d65b2b72caacf7d850b3942b2a",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "3b23a32a63219f51a5298bc55a65ecee866e79d0",
              "lessThan": "bddc09212c24934643bd44fc794748d2bbb3b6cd",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "176188cff67ec1aa55103647b61d02315cc38e98",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "1fc205d9e400f069ebf30d3faa6ec2bab2cbd7b4",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "4d0ae760c02c98fc78b78d3a0509896bc648ad1c",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "5.4.103",
              "lessThan": "5.5",
              "versionType": "semver",
              "status": "affected"
            },
            {
              "version": "5.10.21",
              "lessThan": "5.11",
              "versionType": "semver",
              "status": "affected"
            },
            {
              "version": "5.11.4",
              "lessThan": "5.12",
              "versionType": "semver",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "drivers/net/tap.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "5.12",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "5.12",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.191",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.160",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.114",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.34",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.0.11",
              "lessThanOrEqual": "7.0.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.1",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Primary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "baseScore": 5.5,
          "baseSeverity": "MEDIUM",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 3.6
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-401"
        }
      ]
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "operator": "OR",
          "negate": false,
          "cpeMatch": [
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "5.4.103",
              "versionEndExcluding": "5.5",
              "matchCriteriaId": "77F47A48-724C-4A8A-BE16-F2C832EECA05"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "5.10.21",
              "versionEndExcluding": "5.11",
              "matchCriteriaId": "FA8451E2-8B08-45A9-AEC4-3F6C9C651E35"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "5.11.4",
              "versionEndExcluding": "6.18.34",
              "matchCriteriaId": "0B6E32E7-34D9-4D94-B9F6-8D3A2D90FF06"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "6.19",
              "versionEndExcluding": "7.0.11",
              "matchCriteriaId": "0520D091-FC52-4A50-AF07-70AE7D08B750"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*",
              "matchCriteriaId": "B1EF7059-E670-45F4-B422-54C40FA86390"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*",
              "matchCriteriaId": "0D38F0BF-A728-4133-A358-D44A2F7EE6D6"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:*",
              "matchCriteriaId": "EC732D08-5F7B-46D9-B154-E60C7F4F0A97"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:*",
              "matchCriteriaId": "E5910A9D-F60A-409A-B486-FE66BFEBA9B9"
            }
          ]
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/05305e832be7b9d65b2b72caacf7d850b3942b2a",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://git.kernel.org/stable/c/37d028a473b0826ad5970b52b791db4a29a23627",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/4b6dcfe0e3dfffd8057a4fc99b3f096c45709905",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/719007c3492f0f1f9e9cdbed8ac45ba45bb13eeb",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://git.kernel.org/stable/c/8197905d97099d8b1e3883112bbb497abd20f9f0",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/bddc09212c24934643bd44fc794748d2bbb3b6cd",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ]
    }
  ]
}