CVE-2026-43040 (GCVE-0-2026-43040)

Vulnerability from cvelistv5 – Published: 2026-05-01 14:15 – Updated: 2026-05-01 14:15
VLAI?
Title
net: ipv6: ndisc: fix ndisc_ra_useropt to initialize nduseropt_padX fields to zero to prevent an info-leak
Summary
In the Linux kernel, the following vulnerability has been resolved: net: ipv6: ndisc: fix ndisc_ra_useropt to initialize nduseropt_padX fields to zero to prevent an info-leak When processing Router Advertisements with user options the kernel builds an RTM_NEWNDUSEROPT netlink message. The nduseroptmsg struct has three padding fields that are never zeroed and can leak kernel data The fix is simple, just zeroes the padding fields.
Severity ?
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 31910575a9de61e78065e93846e8e7a4894a18bf , < 1da9023f6b071a38e5430ffbce4b70b2b1ac4f9c (git)
Affected: 31910575a9de61e78065e93846e8e7a4894a18bf , < 2fe4d0ba690a69ad6ae9f7ab9bdc96e02610b648 (git)
Affected: 31910575a9de61e78065e93846e8e7a4894a18bf , < 11d7fe97421cfc81549940c20ed5ac9472d6db05 (git)
Affected: 31910575a9de61e78065e93846e8e7a4894a18bf , < 7f56d87e527bb5a13c3e8b0d5840cb6332822f6d (git)
Affected: 31910575a9de61e78065e93846e8e7a4894a18bf , < 4f810c686fde509d1cdaa706322d9d2531f8f1a4 (git)
Affected: 31910575a9de61e78065e93846e8e7a4894a18bf , < b485eef3d97b7aae55ce669b6de555ec81f3d21c (git)
Affected: 31910575a9de61e78065e93846e8e7a4894a18bf , < ef3645606e4a635d5062a492f22b7f490852ee67 (git)
Affected: 31910575a9de61e78065e93846e8e7a4894a18bf , < ae05340ccaa9d347fe85415609e075545bec589f (git)
Create a notification for this product.
    Linux Linux Affected: 2.6.24
Unaffected: 0 , < 2.6.24 (semver)
Unaffected: 5.10.253 , ≤ 5.10.* (semver)
Unaffected: 5.15.203 , ≤ 5.15.* (semver)
Unaffected: 6.1.168 , ≤ 6.1.* (semver)
Unaffected: 6.6.134 , ≤ 6.6.* (semver)
Unaffected: 6.12.81 , ≤ 6.12.* (semver)
Unaffected: 6.18.22 , ≤ 6.18.* (semver)
Unaffected: 6.19.12 , ≤ 6.19.* (semver)
Unaffected: 7.0 , ≤ * (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/ipv6/ndisc.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "1da9023f6b071a38e5430ffbce4b70b2b1ac4f9c",
              "status": "affected",
              "version": "31910575a9de61e78065e93846e8e7a4894a18bf",
              "versionType": "git"
            },
            {
              "lessThan": "2fe4d0ba690a69ad6ae9f7ab9bdc96e02610b648",
              "status": "affected",
              "version": "31910575a9de61e78065e93846e8e7a4894a18bf",
              "versionType": "git"
            },
            {
              "lessThan": "11d7fe97421cfc81549940c20ed5ac9472d6db05",
              "status": "affected",
              "version": "31910575a9de61e78065e93846e8e7a4894a18bf",
              "versionType": "git"
            },
            {
              "lessThan": "7f56d87e527bb5a13c3e8b0d5840cb6332822f6d",
              "status": "affected",
              "version": "31910575a9de61e78065e93846e8e7a4894a18bf",
              "versionType": "git"
            },
            {
              "lessThan": "4f810c686fde509d1cdaa706322d9d2531f8f1a4",
              "status": "affected",
              "version": "31910575a9de61e78065e93846e8e7a4894a18bf",
              "versionType": "git"
            },
            {
              "lessThan": "b485eef3d97b7aae55ce669b6de555ec81f3d21c",
              "status": "affected",
              "version": "31910575a9de61e78065e93846e8e7a4894a18bf",
              "versionType": "git"
            },
            {
              "lessThan": "ef3645606e4a635d5062a492f22b7f490852ee67",
              "status": "affected",
              "version": "31910575a9de61e78065e93846e8e7a4894a18bf",
              "versionType": "git"
            },
            {
              "lessThan": "ae05340ccaa9d347fe85415609e075545bec589f",
              "status": "affected",
              "version": "31910575a9de61e78065e93846e8e7a4894a18bf",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/ipv6/ndisc.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.24"
            },
            {
              "lessThan": "2.6.24",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.253",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.203",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.168",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.134",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.81",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.22",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.12",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.253",
                  "versionStartIncluding": "2.6.24",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.203",
                  "versionStartIncluding": "2.6.24",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.168",
                  "versionStartIncluding": "2.6.24",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.134",
                  "versionStartIncluding": "2.6.24",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.81",
                  "versionStartIncluding": "2.6.24",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.22",
                  "versionStartIncluding": "2.6.24",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19.12",
                  "versionStartIncluding": "2.6.24",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0",
                  "versionStartIncluding": "2.6.24",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: ipv6: ndisc: fix ndisc_ra_useropt to initialize nduseropt_padX fields to zero to prevent an info-leak\n\nWhen processing Router Advertisements with user options the kernel\nbuilds an RTM_NEWNDUSEROPT netlink message. The nduseroptmsg struct\nhas three padding fields that are never zeroed and can leak kernel data\n\nThe fix is simple, just zeroes the padding fields."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-01T14:15:37.364Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/1da9023f6b071a38e5430ffbce4b70b2b1ac4f9c"
        },
        {
          "url": "https://git.kernel.org/stable/c/2fe4d0ba690a69ad6ae9f7ab9bdc96e02610b648"
        },
        {
          "url": "https://git.kernel.org/stable/c/11d7fe97421cfc81549940c20ed5ac9472d6db05"
        },
        {
          "url": "https://git.kernel.org/stable/c/7f56d87e527bb5a13c3e8b0d5840cb6332822f6d"
        },
        {
          "url": "https://git.kernel.org/stable/c/4f810c686fde509d1cdaa706322d9d2531f8f1a4"
        },
        {
          "url": "https://git.kernel.org/stable/c/b485eef3d97b7aae55ce669b6de555ec81f3d21c"
        },
        {
          "url": "https://git.kernel.org/stable/c/ef3645606e4a635d5062a492f22b7f490852ee67"
        },
        {
          "url": "https://git.kernel.org/stable/c/ae05340ccaa9d347fe85415609e075545bec589f"
        }
      ],
      "title": "net: ipv6: ndisc: fix ndisc_ra_useropt to initialize nduseropt_padX fields to zero to prevent an info-leak",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-43040",
    "datePublished": "2026-05-01T14:15:37.364Z",
    "dateReserved": "2026-05-01T14:12:55.978Z",
    "dateUpdated": "2026-05-01T14:15:37.364Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-43040",
      "date": "2026-05-04",
      "epss": "0.00024",
      "percentile": "0.06795"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-43040\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-05-01T15:16:50.130\",\"lastModified\":\"2026-05-01T15:24:14.893\",\"vulnStatus\":\"Awaiting Analysis\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nnet: ipv6: ndisc: fix ndisc_ra_useropt to initialize nduseropt_padX fields to zero to prevent an info-leak\\n\\nWhen processing Router Advertisements with user options the kernel\\nbuilds an RTM_NEWNDUSEROPT netlink message. The nduseroptmsg struct\\nhas three padding fields that are never zeroed and can leak kernel data\\n\\nThe fix is simple, just zeroes the padding fields.\"}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/11d7fe97421cfc81549940c20ed5ac9472d6db05\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/1da9023f6b071a38e5430ffbce4b70b2b1ac4f9c\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/2fe4d0ba690a69ad6ae9f7ab9bdc96e02610b648\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/4f810c686fde509d1cdaa706322d9d2531f8f1a4\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/7f56d87e527bb5a13c3e8b0d5840cb6332822f6d\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/ae05340ccaa9d347fe85415609e075545bec589f\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/b485eef3d97b7aae55ce669b6de555ec81f3d21c\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/ef3645606e4a635d5062a492f22b7f490852ee67\",\"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.