Vulnerability-Lookup

UBUNTU-CVE-2026-98493 (CVE-2026-98493)

Vulnerability from osv_ubuntu – Published: 2026-10-18 16:17 – Updated: 2026-10-30 19:01 – Source website

Details

In the Linux kernel, the following vulnerability has been resolved: net: ipconfig: bound DHCP option construction ic_dhcp_init_options() appends the hostname (option 12), vendor-class (option 60) and client-ID (option 61) options into the fixed 312-byte bootp_pkt.exten[] buffer. Only the client-ID branch checked the remaining space; the hostname and vendor-class writes were unbounded. A 64-byte hostname together with the maximum 252-byte dhcpclass= identifier needs 18 + (2 + 64) + (2 + 252) = 338 of the 312 available bytes even before the terminating END marker, so the vendor-class memcpy runs past the end of exten[]. With CONFIG_FORTIFY_SOURCE this is reported as a field-spanning write and, when the kernel is booted with panic_on_warn=1, aborts boot with a panic. Route the optional options through a common helper that makes sure the option, its 2-byte header and the END marker all fit and drops an option that would not. Configurations with short options keep sending exactly the same bytes as before.

Severity

N/A (UNKNOWN)

low

References

URL

Type

	https://ubuntu.com/security/CVE-2026-98493	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-98493	REPORT
	https://git.kernel.org/stable/c/24e79508b237dd2a6…	REPORT
	https://git.kernel.org/stable/c/e47a1958e12abc3a1…	REPORT
	https://git.kernel.org/stable/c/abcba6f080c63e403…	REPORT
	https://git.kernel.org/stable/c/cbaad2922bd5d4d30…	REPORT

JSON

To clipboard

Loading 1.0 MB of JSON…

CVE-2026-98493 (GCVE-0-2026-98493)

Vulnerability from cvelistv5 – Published: 2026-10-18 15:16 – Updated: 2026-10-30 12:38

Title

net: ipconfig: bound DHCP option construction

Summary

Severity

No CVSS data available.

Assigner

Linux CNA under the mitre root

CNA scorecard D 53/100 over 6794 records in the last 180 days details

References

8 references

URL	Tags
https://git.kernel.org/stable/c/e0a221cec0e0ee437…
https://git.kernel.org/stable/c/ca811550b9fa87e02…
https://git.kernel.org/stable/c/d8016c82acdd7eaa4…
https://git.kernel.org/stable/c/38a6a118260ebfc82…
https://git.kernel.org/stable/c/abcba6f080c63e403…
https://git.kernel.org/stable/c/24e79508b237dd2a6…
https://git.kernel.org/stable/c/cbaad2922bd5d4d30…
https://git.kernel.org/stable/c/e47a1958e12abc3a1…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 130c0f47fdf9c533deb1136cad5136f6cb7020f0 , < e0a221cec0e0ee437680ae0314a4b166509442c5 (git) Affected: 130c0f47fdf9c533deb1136cad5136f6cb7020f0 , < ca811550b9fa87e02845b4a332d194c2304d933f (git) Affected: 130c0f47fdf9c533deb1136cad5136f6cb7020f0 , < d8016c82acdd7eaa462e1f38a962b15d8c6a650b (git) Affected: 130c0f47fdf9c533deb1136cad5136f6cb7020f0 , < 38a6a118260ebfc82d0c653194d616bdfbd236ac (git) Affected: 130c0f47fdf9c533deb1136cad5136f6cb7020f0 , < abcba6f080c63e403037ecdffde43170d242376a (git) Affected: 130c0f47fdf9c533deb1136cad5136f6cb7020f0 , < 24e79508b237dd2a69bc6fb6ac5cf7f126178307 (git) Affected: 130c0f47fdf9c533deb1136cad5136f6cb7020f0 , < cbaad2922bd5d4d303055ae9afecc8999e6b40c9 (git) Affected: 130c0f47fdf9c533deb1136cad5136f6cb7020f0 , < e47a1958e12abc3a17b5231a4f21c8f1bf662e08 (git)
Linux	Linux	Affected: 2.6.36 Unaffected: 0 , < 2.6.36 (semver) Unaffected: 5.10.273 , ≤ 5.10.* (semver) Unaffected: 5.15.224 , ≤ 5.15.* (semver) Unaffected: 6.1.191 , ≤ 6.1.* (semver) Unaffected: 6.6.160 , ≤ 6.6.* (semver) Unaffected: 6.12.112 , ≤ 6.12.* (semver) Unaffected: 6.18.55 , ≤ 6.18.* (semver) Unaffected: 7.2.9 , ≤ 7.2.* (semver) Unaffected: 7.3 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/ipv4/ipconfig.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "e0a221cec0e0ee437680ae0314a4b166509442c5",
              "status": "affected",
              "version": "130c0f47fdf9c533deb1136cad5136f6cb7020f0",
              "versionType": "git"
            },
            {
              "lessThan": "ca811550b9fa87e02845b4a332d194c2304d933f",
              "status": "affected",
              "version": "130c0f47fdf9c533deb1136cad5136f6cb7020f0",
              "versionType": "git"
            },
            {
              "lessThan": "d8016c82acdd7eaa462e1f38a962b15d8c6a650b",
              "status": "affected",
              "version": "130c0f47fdf9c533deb1136cad5136f6cb7020f0",
              "versionType": "git"
            },
            {
              "lessThan": "38a6a118260ebfc82d0c653194d616bdfbd236ac",
              "status": "affected",
              "version": "130c0f47fdf9c533deb1136cad5136f6cb7020f0",
              "versionType": "git"
            },
            {
              "lessThan": "abcba6f080c63e403037ecdffde43170d242376a",
              "status": "affected",
              "version": "130c0f47fdf9c533deb1136cad5136f6cb7020f0",
              "versionType": "git"
            },
            {
              "lessThan": "24e79508b237dd2a69bc6fb6ac5cf7f126178307",
              "status": "affected",
              "version": "130c0f47fdf9c533deb1136cad5136f6cb7020f0",
              "versionType": "git"
            },
            {
              "lessThan": "cbaad2922bd5d4d303055ae9afecc8999e6b40c9",
              "status": "affected",
              "version": "130c0f47fdf9c533deb1136cad5136f6cb7020f0",
              "versionType": "git"
            },
            {
              "lessThan": "e47a1958e12abc3a17b5231a4f21c8f1bf662e08",
              "status": "affected",
              "version": "130c0f47fdf9c533deb1136cad5136f6cb7020f0",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/ipv4/ipconfig.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.36"
            },
            {
              "lessThan": "2.6.36",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.273",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.224",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.191",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.160",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.112",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.55",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.9",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.273",
                  "versionStartIncluding": "2.6.36",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.224",
                  "versionStartIncluding": "2.6.36",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.191",
                  "versionStartIncluding": "2.6.36",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.160",
                  "versionStartIncluding": "2.6.36",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.112",
                  "versionStartIncluding": "2.6.36",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.55",
                  "versionStartIncluding": "2.6.36",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.9",
                  "versionStartIncluding": "2.6.36",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3",
                  "versionStartIncluding": "2.6.36",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: ipconfig: bound DHCP option construction\n\nic_dhcp_init_options() appends the hostname (option 12), vendor-class\n(option 60) and client-ID (option 61) options into the fixed 312-byte\nbootp_pkt.exten[] buffer.  Only the client-ID branch checked the\nremaining space; the hostname and vendor-class writes were unbounded.\n\nA 64-byte hostname together with the maximum 252-byte dhcpclass=\nidentifier needs 18 + (2 + 64) + (2 + 252) = 338 of the 312 available\nbytes even before the terminating END marker, so the vendor-class memcpy\nruns past the end of exten[].  With CONFIG_FORTIFY_SOURCE this is\nreported as a field-spanning write and, when the kernel is booted with\npanic_on_warn=1, aborts boot with a panic.\n\nRoute the optional options through a common helper that makes sure the\noption, its 2-byte header and the END marker all fit and drops an option\nthat would not.  Configurations with short options keep sending exactly\nthe same bytes as before."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-30T12:38:18.516Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/e0a221cec0e0ee437680ae0314a4b166509442c5"
        },
        {
          "url": "https://git.kernel.org/stable/c/ca811550b9fa87e02845b4a332d194c2304d933f"
        },
        {
          "url": "https://git.kernel.org/stable/c/d8016c82acdd7eaa462e1f38a962b15d8c6a650b"
        },
        {
          "url": "https://git.kernel.org/stable/c/38a6a118260ebfc82d0c653194d616bdfbd236ac"
        },
        {
          "url": "https://git.kernel.org/stable/c/abcba6f080c63e403037ecdffde43170d242376a"
        },
        {
          "url": "https://git.kernel.org/stable/c/24e79508b237dd2a69bc6fb6ac5cf7f126178307"
        },
        {
          "url": "https://git.kernel.org/stable/c/cbaad2922bd5d4d303055ae9afecc8999e6b40c9"
        },
        {
          "url": "https://git.kernel.org/stable/c/e47a1958e12abc3a17b5231a4f21c8f1bf662e08"
        }
      ],
      "title": "net: ipconfig: bound DHCP option construction",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-98493",
    "datePublished": "2026-10-18T15:16:22.301Z",
    "dateReserved": "2026-09-25T10:25:14.353Z",
    "dateUpdated": "2026-10-30T12:38:18.516Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

Order JSON

Publication & reservation Sightings KEV catalogs Other timestamps

Loading timeline…

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted