CVE-2026-43190 (GCVE-0-2026-43190)
Vulnerability from cvelistv5
Published
2026-05-06 11:27
Modified
2026-05-11 22:19
Severity ?
8.2 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: netfilter: xt_tcpmss: check remaining length before reading optlen Quoting reporter: In net/netfilter/xt_tcpmss.c (lines 53-68), the TCP option parser reads op[i+1] directly without validating the remaining option length. If the last byte of the option field is not EOL/NOP (0/1), the code attempts to index op[i+1]. In the case where i + 1 == optlen, this causes an out-of-bounds read, accessing memory past the optlen boundary (either reading beyond the stack buffer _opt or the following payload).
References
Impacted products
Vendor Product Version
Linux Linux Version: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2
Version: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2
Version: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2
Version: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2
Version: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2
Version: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2
Version: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2
Version: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/netfilter/xt_tcpmss.c"
          ],
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        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
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          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.12"
            },
            {
              "lessThan": "2.6.12",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.252",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.202",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.165",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.128",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.75",
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            },
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              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.16",
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            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.6",
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            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
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                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: xt_tcpmss: check remaining length before reading optlen\n\nQuoting reporter:\n  In net/netfilter/xt_tcpmss.c (lines 53-68), the TCP option parser reads\n op[i+1] directly without validating the remaining option length.\n\n  If the last byte of the option field is not EOL/NOP (0/1), the code attempts\n  to index op[i+1]. In the case where i + 1 == optlen, this causes an\n  out-of-bounds read, accessing memory past the optlen boundary\n  (either reading beyond the stack buffer _opt or the\n  following payload)."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 8.2,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H",
            "version": "3.1"
          }
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-11T22:19:35.257Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/f895191dc32c53eaf443b6443fe40945b2f92287"
        },
        {
          "url": "https://git.kernel.org/stable/c/cd5beda7e0e32865e214f28034bb92c1cecff885"
        },
        {
          "url": "https://git.kernel.org/stable/c/eaedc0bc18be46fe7f58170e967959a932c4f824"
        },
        {
          "url": "https://git.kernel.org/stable/c/07a9b32eaae792ff7d0fcac14d8920c937c0a9c3"
        },
        {
          "url": "https://git.kernel.org/stable/c/8b300f726640c48c3edfe9c453334dd801f4b74e"
        },
        {
          "url": "https://git.kernel.org/stable/c/5e13d0a37666955b6cfddc0f73cb40ed645b8a05"
        },
        {
          "url": "https://git.kernel.org/stable/c/f6c412dcfd76b0516d51aa847d8f4c7b70381b09"
        },
        {
          "url": "https://git.kernel.org/stable/c/735ee8582da3d239eb0c7a53adca61b79fb228b3"
        }
      ],
      "title": "netfilter: xt_tcpmss: check remaining length before reading optlen",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-43190",
    "datePublished": "2026-05-06T11:27:59.798Z",
    "dateReserved": "2026-05-01T14:12:55.992Z",
    "dateUpdated": "2026-05-11T22:19:35.257Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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