← Back to CVE Explorer

CVE-2026-63932

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: iio: chemical: mhz19b: reject oversized serial replies mhz19b_receive_buf() appends each serdev chunk into the fixed MHZ19B_CMD_SIZE receive buffer and advances buf_idx by len without checking that the chunk fits in the remaining space. A large callback can therefore overflow st->buf before the command path validates the reply. Reset the reply state before each command and reject oversized serial replies before copying them into the fixed buffer. When an oversized reply is detected, wake the waiter and report -EMSGSIZE instead of overwriting st->buf.

Severity
MEDIUM
CVSS score
5.5 (v3.1)
Vulnerability status
Analyzed
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-07-19 16:17:11.633000
Last modified
2026-10-30 14:28:40.690000
View original CVE JSON 
{
  "id": "CVE-2026-63932",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-07-19T16:17:11.633",
  "lastModified": "2026-10-30T14:28:40.690",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\niio: chemical: mhz19b: reject oversized serial replies\n\nmhz19b_receive_buf() appends each serdev chunk into the fixed\nMHZ19B_CMD_SIZE receive buffer and advances buf_idx by len without\nchecking that the chunk fits in the remaining space. A large callback\ncan therefore overflow st->buf before the command path validates the\nreply.\n\nReset the reply state before each command and reject oversized serial\nreplies before copying them into the fixed buffer. When an oversized\nreply is detected, wake the waiter and report -EMSGSIZE instead of\noverwriting st->buf."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "drivers/iio/chemical/mhz19b.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "4572a70b3681e38055c78d12fb68cd147bdbee7d",
              "lessThan": "a5a05410cb34bfa486d63684cdc1f87a3b13f20a",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "4572a70b3681e38055c78d12fb68cd147bdbee7d",
              "lessThan": "ea69e7a6efa88ef32090a91064c362738cc19ddd",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "4572a70b3681e38055c78d12fb68cd147bdbee7d",
              "lessThan": "673478bc29cf72010faaf293c1c8c667393335a0",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "drivers/iio/chemical/mhz19b.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "6.16",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "6.16",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.35",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.0.12",
              "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": "NVD-CWE-noinfo"
        }
      ]
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "operator": "OR",
          "negate": false,
          "cpeMatch": [
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "6.16",
              "versionEndExcluding": "6.18.35",
              "matchCriteriaId": "7BC83D47-7720-40AC-85ED-873326493894"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "6.19",
              "versionEndExcluding": "7.0.12",
              "matchCriteriaId": "9161A938-0FA8-44BC-95FE-C5A271601AB3"
            },
            {
              "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"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:*",
              "matchCriteriaId": "81DFF19E-9CF8-49C6-8C36-1E4038622933"
            }
          ]
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/673478bc29cf72010faaf293c1c8c667393335a0",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://git.kernel.org/stable/c/a5a05410cb34bfa486d63684cdc1f87a3b13f20a",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://git.kernel.org/stable/c/ea69e7a6efa88ef32090a91064c362738cc19ddd",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ]
    }
  ]
}