Vulnerability-Lookup

GHSA-VH4P-87XG-JC4X

Vulnerability from github – Published: 2026-06-23 18:31 – Updated: 2026-06-23 18:31

Details

dhcpcd through 10.3.2, fixed in commit 5733d3c, contains a heap use-after-free vulnerability that allows unauthenticated same-link attackers to crash the daemon by sending a crafted DHCPv6 RENEW reply with RFC6603 OPTION_PD_EXCLUDE and both preferred and valid lifetimes set to zero. Attackers acting as or impersonating a DHCPv6 server can trigger dhcp6_deprecatedele() to free a delegated child address while an outer TAILQ_FOREACH_SAFE iterator in dhcp6_deprecateaddrs() still holds the freed pointer, causing a use-after-free when TAILQ_REMOVE is reached.

Severity

5.3 (Medium)


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

6.0 (Medium)


                  
                    CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

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{
  "affected": [],
  "aliases": [
    "CVE-2026-56113"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-416"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-06-23T17:17:09Z",
    "severity": "MODERATE"
  },
  "details": "dhcpcd through 10.3.2, fixed in commit 5733d3c, contains a heap use-after-free vulnerability that allows unauthenticated same-link attackers to crash the daemon by sending a crafted DHCPv6 RENEW reply with RFC6603 OPTION_PD_EXCLUDE and both preferred and valid lifetimes set to zero. Attackers acting as or impersonating a DHCPv6 server can trigger dhcp6_deprecatedele() to free a delegated child address while an outer TAILQ_FOREACH_SAFE iterator in dhcp6_deprecateaddrs() still holds the freed pointer, causing a use-after-free when TAILQ_REMOVE is reached.",
  "id": "GHSA-vh4p-87xg-jc4x",
  "modified": "2026-06-23T18:31:43Z",
  "published": "2026-06-23T18:31:43Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-56113"
    },
    {
      "type": "WEB",
      "url": "https://github.com/NetworkConfiguration/dhcpcd/commit/5733d3c59a5651f64357ac11c98b4f39895c8d25"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/dhcpcd-heap-use-after-free-in-dhcp6-deprecateaddrs-via-dhcpv6-renew"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
      "type": "CVSS_V4"
    }
  ]
}

CVE-2026-56113 (GCVE-0-2026-56113)

Vulnerability from cvelistv5 – Published: 2026-06-23 16:05 – Updated: 2026-06-23 17:58 X_Open Source

Title

dhcpcd Heap Use-After-Free in dhcp6_deprecateaddrs via DHCPv6 RENEW

Summary

Severity

6 (Medium)


                        
                          CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

5.3 (Medium)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-416 - Use After Free

Assigner

VulnCheck

References

2 references

URL	Tags
https://github.com/NetworkConfiguration/dhcpcd/co…	patch
https://www.vulncheck.com/advisories/dhcpcd-heap-…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
NetworkConfiguration	dhcpcd	Affected: 0 , ≤ 10.3.2 (semver) Unaffected: 5733d3c59a5651f64357ac11c98b4f39895c8d25 (git)

Date Public

2026-06-22 00:00

Credits

CuB3y0nd VulnCheck

Show details on NVD website

JSON

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-56113",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-06-23T17:58:06.379364Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-06-23T17:58:21.174Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "affected",
          "product": "dhcpcd",
          "repo": "https://github.com/NetworkConfiguration/dhcpcd",
          "vendor": "NetworkConfiguration",
          "versions": [
            {
              "lessThanOrEqual": "10.3.2",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "5733d3c59a5651f64357ac11c98b4f39895c8d25",
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          "lang": "en",
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        }
      ],
      "metrics": [
        {
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            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
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            "baseSeverity": "MEDIUM",
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            "subIntegrityImpact": "NONE",
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            "vulnAvailabilityImpact": "HIGH",
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            "vulnIntegrityImpact": "NONE",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
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            {
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              "description": "Use After Free",
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      "providerMetadata": {
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          "url": "https://www.vulncheck.com/advisories/dhcpcd-heap-use-after-free-in-dhcp6-deprecateaddrs-via-dhcpv6-renew"
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
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        "x_open-source"
      ],
      "title": "dhcpcd Heap Use-After-Free in dhcp6_deprecateaddrs via DHCPv6 RENEW",
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  "cveMetadata": {
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    "datePublished": "2026-06-23T16:05:59.768Z",
    "dateReserved": "2026-06-18T19:15:10.650Z",
    "dateUpdated": "2026-06-23T17:58:21.174Z",
    "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-VH4P-87XG-JC4X

CVE-2026-56113 (GCVE-0-2026-56113)

Tags

Sightings

Nomenclature