CVE-2026-63868 (GCVE-0-2026-63868)

Vulnerability from cvelistv5 – Published: 2026-07-19 14:18 – Updated: 2026-07-19 14:18
VLAI
Title
net: garp: fix unsigned integer underflow in garp_pdu_parse_attr
Summary
In the Linux kernel, the following vulnerability has been resolved: net: garp: fix unsigned integer underflow in garp_pdu_parse_attr The receive-side GARP attribute parser computes dlen with reversed operands: dlen = sizeof(*ga) - ga->len; ga->len is the on-wire attribute length and includes the GARP attribute header. For normal attributes with data, ga->len is larger than sizeof(*ga), so the subtraction underflows in unsigned arithmetic. The resulting value is later passed to garp_attr_lookup(), whose length argument is u8. After truncation, the parsed data length usually no longer matches the length stored for locally registered attributes, so received Join/Leave events are ignored. This breaks the GARP receive path for common attributes, such as GVRP VLAN registration attributes. Compute the data length as the attribute length minus the header length.
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: eca9ebac651f774d8b10fce7c5d173c3c3d3394f , < 29f28172afb2ae7b31e9bf3e978396f20b381688 (git)
Affected: eca9ebac651f774d8b10fce7c5d173c3c3d3394f , < 973cf7c433d27f4d9556d0b7c332543be7ed7a6e (git)
Affected: eca9ebac651f774d8b10fce7c5d173c3c3d3394f , < d8dcd14aa886b8effd83022c550669f4f262854b (git)
Affected: eca9ebac651f774d8b10fce7c5d173c3c3d3394f , < 74e02121be1dcc0efcd56ebdf0171d6129105659 (git)
Affected: eca9ebac651f774d8b10fce7c5d173c3c3d3394f , < d4c86ea09ae3e63ee5aa86e941fcc38e0e39874a (git)
Affected: eca9ebac651f774d8b10fce7c5d173c3c3d3394f , < 04e22fefac1af3e32f245e9045382348773b5d59 (git)
Affected: eca9ebac651f774d8b10fce7c5d173c3c3d3394f , < a11f1a671b1361f0f1278dc0041374f2730df73f (git)
Affected: eca9ebac651f774d8b10fce7c5d173c3c3d3394f , < 16e408e607a94b646fb14a2a98422c6877ae4b3c (git)
Create a notification for this product.
Linux Linux Affected: 2.6.27
Unaffected: 0 , < 2.6.27 (semver)
Unaffected: 5.10.259 , ≤ 5.10.* (semver)
Unaffected: 5.15.210 , ≤ 5.15.* (semver)
Unaffected: 6.1.176 , ≤ 6.1.* (semver)
Unaffected: 6.6.143 , ≤ 6.6.* (semver)
Unaffected: 6.12.94 , ≤ 6.12.* (semver)
Unaffected: 6.18.36 , ≤ 6.18.* (semver)
Unaffected: 7.0.13 , ≤ 7.0.* (semver)
Unaffected: 7.1 , ≤ * (original_commit_for_fix)
Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/802/garp.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "29f28172afb2ae7b31e9bf3e978396f20b381688",
              "status": "affected",
              "version": "eca9ebac651f774d8b10fce7c5d173c3c3d3394f",
              "versionType": "git"
            },
            {
              "lessThan": "973cf7c433d27f4d9556d0b7c332543be7ed7a6e",
              "status": "affected",
              "version": "eca9ebac651f774d8b10fce7c5d173c3c3d3394f",
              "versionType": "git"
            },
            {
              "lessThan": "d8dcd14aa886b8effd83022c550669f4f262854b",
              "status": "affected",
              "version": "eca9ebac651f774d8b10fce7c5d173c3c3d3394f",
              "versionType": "git"
            },
            {
              "lessThan": "74e02121be1dcc0efcd56ebdf0171d6129105659",
              "status": "affected",
              "version": "eca9ebac651f774d8b10fce7c5d173c3c3d3394f",
              "versionType": "git"
            },
            {
              "lessThan": "d4c86ea09ae3e63ee5aa86e941fcc38e0e39874a",
              "status": "affected",
              "version": "eca9ebac651f774d8b10fce7c5d173c3c3d3394f",
              "versionType": "git"
            },
            {
              "lessThan": "04e22fefac1af3e32f245e9045382348773b5d59",
              "status": "affected",
              "version": "eca9ebac651f774d8b10fce7c5d173c3c3d3394f",
              "versionType": "git"
            },
            {
              "lessThan": "a11f1a671b1361f0f1278dc0041374f2730df73f",
              "status": "affected",
              "version": "eca9ebac651f774d8b10fce7c5d173c3c3d3394f",
              "versionType": "git"
            },
            {
              "lessThan": "16e408e607a94b646fb14a2a98422c6877ae4b3c",
              "status": "affected",
              "version": "eca9ebac651f774d8b10fce7c5d173c3c3d3394f",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/802/garp.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.27"
            },
            {
              "lessThan": "2.6.27",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.259",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.210",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.176",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.143",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.94",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.36",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.13",
              "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": "5.10.259",
                  "versionStartIncluding": "2.6.27",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.210",
                  "versionStartIncluding": "2.6.27",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.176",
                  "versionStartIncluding": "2.6.27",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.143",
                  "versionStartIncluding": "2.6.27",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.94",
                  "versionStartIncluding": "2.6.27",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.36",
                  "versionStartIncluding": "2.6.27",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0.13",
                  "versionStartIncluding": "2.6.27",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1",
                  "versionStartIncluding": "2.6.27",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: garp: fix unsigned integer underflow in garp_pdu_parse_attr\n\nThe receive-side GARP attribute parser computes dlen with reversed\noperands:\n\n        dlen = sizeof(*ga) - ga-\u003elen;\n\nga-\u003elen is the on-wire attribute length and includes the GARP attribute\nheader. For normal attributes with data, ga-\u003elen is larger than\nsizeof(*ga), so the subtraction underflows in unsigned arithmetic.\n\nThe resulting value is later passed to garp_attr_lookup(), whose length\nargument is u8. After truncation, the parsed data length usually no\nlonger matches the length stored for locally registered attributes, so\nreceived Join/Leave events are ignored. This breaks the GARP receive path\nfor common attributes, such as GVRP VLAN registration attributes.\n\nCompute the data length as the attribute length minus the header length."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-19T14:18:37.823Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/29f28172afb2ae7b31e9bf3e978396f20b381688"
        },
        {
          "url": "https://git.kernel.org/stable/c/973cf7c433d27f4d9556d0b7c332543be7ed7a6e"
        },
        {
          "url": "https://git.kernel.org/stable/c/d8dcd14aa886b8effd83022c550669f4f262854b"
        },
        {
          "url": "https://git.kernel.org/stable/c/74e02121be1dcc0efcd56ebdf0171d6129105659"
        },
        {
          "url": "https://git.kernel.org/stable/c/d4c86ea09ae3e63ee5aa86e941fcc38e0e39874a"
        },
        {
          "url": "https://git.kernel.org/stable/c/04e22fefac1af3e32f245e9045382348773b5d59"
        },
        {
          "url": "https://git.kernel.org/stable/c/a11f1a671b1361f0f1278dc0041374f2730df73f"
        },
        {
          "url": "https://git.kernel.org/stable/c/16e408e607a94b646fb14a2a98422c6877ae4b3c"
        }
      ],
      "title": "net: garp: fix unsigned integer underflow in garp_pdu_parse_attr",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-63868",
    "datePublished": "2026-07-19T14:18:37.823Z",
    "dateReserved": "2026-07-19T07:54:57.017Z",
    "dateUpdated": "2026-07-19T14:18:37.823Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-63868",
      "date": "2026-07-20",
      "epss": "0.00165",
      "percentile": "0.06063"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-63868\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-07-19T15:16:53.740\",\"lastModified\":\"2026-07-19T15:16:53.740\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nnet: garp: fix unsigned integer underflow in garp_pdu_parse_attr\\n\\nThe receive-side GARP attribute parser computes dlen with reversed\\noperands:\\n\\n        dlen = sizeof(*ga) - ga-\u003elen;\\n\\nga-\u003elen is the on-wire attribute length and includes the GARP attribute\\nheader. For normal attributes with data, ga-\u003elen is larger than\\nsizeof(*ga), so the subtraction underflows in unsigned arithmetic.\\n\\nThe resulting value is later passed to garp_attr_lookup(), whose length\\nargument is u8. After truncation, the parsed data length usually no\\nlonger matches the length stored for locally registered attributes, so\\nreceived Join/Leave events are ignored. This breaks the GARP receive path\\nfor common attributes, such as GVRP VLAN registration attributes.\\n\\nCompute the data length as the attribute length minus the header length.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"net/802/garp.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"eca9ebac651f774d8b10fce7c5d173c3c3d3394f\",\"lessThan\":\"29f28172afb2ae7b31e9bf3e978396f20b381688\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"eca9ebac651f774d8b10fce7c5d173c3c3d3394f\",\"lessThan\":\"973cf7c433d27f4d9556d0b7c332543be7ed7a6e\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"eca9ebac651f774d8b10fce7c5d173c3c3d3394f\",\"lessThan\":\"d8dcd14aa886b8effd83022c550669f4f262854b\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"eca9ebac651f774d8b10fce7c5d173c3c3d3394f\",\"lessThan\":\"74e02121be1dcc0efcd56ebdf0171d6129105659\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"eca9ebac651f774d8b10fce7c5d173c3c3d3394f\",\"lessThan\":\"d4c86ea09ae3e63ee5aa86e941fcc38e0e39874a\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"eca9ebac651f774d8b10fce7c5d173c3c3d3394f\",\"lessThan\":\"04e22fefac1af3e32f245e9045382348773b5d59\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"eca9ebac651f774d8b10fce7c5d173c3c3d3394f\",\"lessThan\":\"a11f1a671b1361f0f1278dc0041374f2730df73f\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"eca9ebac651f774d8b10fce7c5d173c3c3d3394f\",\"lessThan\":\"16e408e607a94b646fb14a2a98422c6877ae4b3c\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"net/802/garp.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"2.6.27\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"2.6.27\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.10.259\",\"lessThanOrEqual\":\"5.10.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.15.210\",\"lessThanOrEqual\":\"5.15.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.1.176\",\"lessThanOrEqual\":\"6.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.6.143\",\"lessThanOrEqual\":\"6.6.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.94\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.36\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.0.13\",\"lessThanOrEqual\":\"7.0.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/04e22fefac1af3e32f245e9045382348773b5d59\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/16e408e607a94b646fb14a2a98422c6877ae4b3c\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/29f28172afb2ae7b31e9bf3e978396f20b381688\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/74e02121be1dcc0efcd56ebdf0171d6129105659\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/973cf7c433d27f4d9556d0b7c332543be7ed7a6e\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/a11f1a671b1361f0f1278dc0041374f2730df73f\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/d4c86ea09ae3e63ee5aa86e941fcc38e0e39874a\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/d8dcd14aa886b8effd83022c550669f4f262854b\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





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.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.