Vulnerability-Lookup

GHSA-G8C6-C8PH-PP93

Vulnerability from github – Published: 2026-07-19 18:31 – Updated: 2026-07-20 15:31

Details

In the Linux kernel, the following vulnerability has been resolved:

ethtool: cmis: validate start_cmd_payload_size from module

The CMIS firmware update code reads start_cmd_payload_size from the module's FW Management Features CDB reply and uses it directly as the byte count for memcpy. The destination buffer is 112 bytes (ETHTOOL_CMIS_CDB_LPL_MAX_PL_LENGTH - 8). So a malicious module (or corrupted response) can cause a OOB write later on in cmis_fw_update_start_download().

Let's error out. If modules that expect longer LPL writes actually exist we should revisit.

struct cmis_cdb_start_fw_download_pl's definition has to move, no change there.

Severity

7.8 (High)


                  
                    CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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{
  "affected": [],
  "aliases": [
    "CVE-2026-63995"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-19T16:17:39Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nethtool: cmis: validate start_cmd_payload_size from module\n\nThe CMIS firmware update code reads start_cmd_payload_size from\nthe module\u0027s FW Management Features CDB reply and uses it directly\nas the byte count for memcpy. The destination buffer is 112 bytes\n(ETHTOOL_CMIS_CDB_LPL_MAX_PL_LENGTH - 8). So a malicious\nmodule (or corrupted response) can cause a OOB write later on in\ncmis_fw_update_start_download().\n\nLet\u0027s error out. If modules that expect longer LPL writes actually\nexist we should revisit.\n\nstruct cmis_cdb_start_fw_download_pl\u0027s definition has to move,\nno change there.",
  "id": "GHSA-g8c6-c8ph-pp93",
  "modified": "2026-07-20T15:31:54Z",
  "published": "2026-07-19T18:31:48Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-63995"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0696709e951be54c699664adf546d16e28974d53"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/12c2496a71f82f63617971ca9b730dffa05cf58b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/63112b4515469d00008452d9cfe3fb3bf1aa2df3"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a46340da00385be7fb16c62425ebc20006f2d5d8"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-63995 (GCVE-0-2026-63995)

Vulnerability from cvelistv5 – Published: 2026-07-19 14:56 – Updated: 2026-07-20 13:42

Title

ethtool: cmis: validate start_cmd_payload_size from module

Summary

In the Linux kernel, the following vulnerability has been resolved: ethtool: cmis: validate start_cmd_payload_size from module The CMIS firmware update code reads start_cmd_payload_size from the module's FW Management Features CDB reply and uses it directly as the byte count for memcpy. The destination buffer is 112 bytes (ETHTOOL_CMIS_CDB_LPL_MAX_PL_LENGTH - 8). So a malicious module (or corrupted response) can cause a OOB write later on in cmis_fw_update_start_download(). Let's error out. If modules that expect longer LPL writes actually exist we should revisit. struct cmis_cdb_start_fw_download_pl's definition has to move, no change there.

Severity

7.8 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Assigner

Linux

References

4 references

URL	Tags
https://git.kernel.org/stable/c/63112b4515469d000…
https://git.kernel.org/stable/c/0696709e951be54c6…
https://git.kernel.org/stable/c/a46340da00385be7f…
https://git.kernel.org/stable/c/12c2496a71f82f636…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: c4f78134d45c9619339c96b4bea380b1d0699788 , < 63112b4515469d00008452d9cfe3fb3bf1aa2df3 (git) Affected: c4f78134d45c9619339c96b4bea380b1d0699788 , < 0696709e951be54c699664adf546d16e28974d53 (git) Affected: c4f78134d45c9619339c96b4bea380b1d0699788 , < a46340da00385be7fb16c62425ebc20006f2d5d8 (git) Affected: c4f78134d45c9619339c96b4bea380b1d0699788 , < 12c2496a71f82f63617971ca9b730dffa05cf58b (git)
Linux	Linux	Affected: 6.11 Unaffected: 0 , < 6.11 (semver) Unaffected: 6.12.93 , ≤ 6.12.* (semver) Unaffected: 6.18.35 , ≤ 6.18.* (semver) Unaffected: 7.0.12 , ≤ 7.0.* (semver) Unaffected: 7.1 , ≤ * (original_commit_for_fix)

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{
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      "affected": [
        {
          "defaultStatus": "unaffected",
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          "programFiles": [
            "net/ethtool/cmis_fw_update.c"
          ],
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          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "63112b4515469d00008452d9cfe3fb3bf1aa2df3",
              "status": "affected",
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              "versionType": "git"
            },
            {
              "lessThan": "0696709e951be54c699664adf546d16e28974d53",
              "status": "affected",
              "version": "c4f78134d45c9619339c96b4bea380b1d0699788",
              "versionType": "git"
            },
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              "versionType": "git"
            },
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              "version": "c4f78134d45c9619339c96b4bea380b1d0699788",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
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          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.11"
            },
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              "lessThan": "6.11",
              "status": "unaffected",
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              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.93",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.35",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.12",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
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        }
      ],
      "cpeApplicability": [
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          "nodes": [
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                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                  "versionStartIncluding": "6.11",
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        }
      ],
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        "dateUpdated": "2026-07-20T13:42:10.891Z",
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    "datePublished": "2026-07-19T14:56:14.580Z",
    "dateReserved": "2026-07-19T07:54:57.026Z",
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    "state": "PUBLISHED"
  },
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}

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.

Action not permitted

GHSA-G8C6-C8PH-PP93

CVE-2026-63995 (GCVE-0-2026-63995)

Tags

Sightings

Nomenclature