Vulnerability-Lookup

GHSA-6R9J-W82P-V45P

Vulnerability from github – Published: 2026-04-30 09:30 – Updated: 2026-04-30 15:30

Details

A specially crafted packet can cause dhclient to overrun its buffer of environment entries. This can result in a crash, but it may be possible to leverage this bug to achieve remote code execution.

Severity ?

7.3 (High)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-42512"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-122"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-04-30T09:16:03Z",
    "severity": "HIGH"
  },
  "details": "As dhclient is building an environment to pass to dhclient-script, it may need to resize the array of string pointers.  The code which expands the array incorrectly calculates its new size when requesting memory, resulting in a heap buffer overrun.\n\nA specially crafted packet can cause dhclient to overrun its buffer of environment entries.  This can result in a crash, but it may be possible to leverage this bug to achieve remote code execution.",
  "id": "GHSA-6r9j-w82p-v45p",
  "modified": "2026-04-30T15:30:39Z",
  "published": "2026-04-30T09:30:25Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-42512"
    },
    {
      "type": "WEB",
      "url": "https://security.freebsd.org/advisories/FreeBSD-SA-26:15.dhclient.asc"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-42512 (GCVE-0-2026-42512)

Vulnerability from cvelistv5 – Published: 2026-04-30 07:58 – Updated: 2026-05-01 15:26

Title

Remotely triggerable out-of-bounds heap write in dhclient

Summary

As dhclient is building an environment to pass to dhclient-script, it may need to resize the array of string pointers. The code which expands the array incorrectly calculates its new size when requesting memory, resulting in a heap buffer overrun. A specially crafted packet can cause dhclient to overrun its buffer of environment entries. This can result in a crash, but it may be possible to leverage this bug to achieve remote code execution.

Severity ?

8.1 (High)


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

CWE

CWE-122 - Heap-based Buffer Overflow

Assigner

freebsd

References

1 reference

URL	Tags
https://security.freebsd.org/advisories/FreeBSD-S…	vendor-advisory

Impacted products

1 product

Vendor	Product	Version
FreeBSD	FreeBSD	Affected: 15.0-RELEASE , < p7 (release) Affected: 14.4-RELEASE , < p3 (release) Affected: 14.3-RELEASE , < p12 (release) Affected: 13.5-RELEASE , < p13 (release)

Date Public ?

2026-04-29 19:00

Credits

Joshua Rogers of AISLE Research Team

Show details on NVD website

JSON

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "HIGH",
              "attackVector": "NETWORK",
              "availabilityImpact": "HIGH",
              "baseScore": 8.1,
              "baseSeverity": "HIGH",
              "confidentialityImpact": "HIGH",
              "integrityImpact": "HIGH",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-42512",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-01T03:55:53.107126Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-05-01T15:26:06.292Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unknown",
          "modules": [
            "dhclient"
          ],
          "product": "FreeBSD",
          "vendor": "FreeBSD",
          "versions": [
            {
              "lessThan": "p7",
              "status": "affected",
              "version": "15.0-RELEASE",
              "versionType": "release"
            },
            {
              "lessThan": "p3",
              "status": "affected",
              "version": "14.4-RELEASE",
              "versionType": "release"
            },
            {
              "lessThan": "p12",
              "status": "affected",
              "version": "14.3-RELEASE",
              "versionType": "release"
            },
            {
              "lessThan": "p13",
              "status": "affected",
              "version": "13.5-RELEASE",
              "versionType": "release"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Joshua Rogers of AISLE Research Team"
        }
      ],
      "datePublic": "2026-04-29T19:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "As dhclient is building an environment to pass to dhclient-script, it may need to resize the array of string pointers.  The code which expands the array incorrectly calculates its new size when requesting memory, resulting in a heap buffer overrun.\n\nA specially crafted packet can cause dhclient to overrun its buffer of environment entries.  This can result in a crash, but it may be possible to leverage this bug to achieve remote code execution."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-122",
              "description": "CWE-122: Heap-based Buffer Overflow",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-04-30T07:58:37.145Z",
        "orgId": "63664ac6-956c-4cba-a5d0-f46076e16109",
        "shortName": "freebsd"
      },
      "references": [
        {
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://security.freebsd.org/advisories/FreeBSD-SA-26:15.dhclient.asc"
        }
      ],
      "title": "Remotely triggerable out-of-bounds heap write in dhclient",
      "x_generator": {
        "engine": "cvelib 1.8.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "63664ac6-956c-4cba-a5d0-f46076e16109",
    "assignerShortName": "freebsd",
    "cveId": "CVE-2026-42512",
    "datePublished": "2026-04-30T07:58:37.145Z",
    "dateReserved": "2026-04-28T05:31:44.956Z",
    "dateUpdated": "2026-05-01T15:26:06.292Z",
    "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.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-6R9J-W82P-V45P

CVE-2026-42512 (GCVE-0-2026-42512)

Tags

Sightings

Nomenclature