CVE-2026-49868 (GCVE-0-2026-49868)

Vulnerability from cvelistv5 – Published: 2026-10-16 16:50 – Updated: 2026-10-16 16:50
VLAI
Title
RIOT: DHCPv6 client _parse_reply() missing sub-option length check leads to size_t underflow and unbounded OOB heap read
Summary
RIOT is an open-source microcontroller operating system designed for Internet of Things devices and other embedded systems. Prior to 2026.07, _parse_reply() in sys/net/application_layer/dhcpv6/client.c omits minimum-length validation before passing IA_PD and IA_NA option bodies to sub-option parsers. A malicious or compromised DHCPv6 server can send a REPLY with an option length smaller than the required structure while MODULE_DHCPV6_CLIENT_IA_PD is enabled, causing _parse_ia_pd_option to read past the option body, size_t underflow, and unbounded out-of-bounds heap reads that can crash the device and may expose or corrupt memory. This issue is fixed in version 2026.07.
Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE
  • CWE-125 - Out-of-bounds Read
  • CWE-191 - Integer Underflow (Wrap or Wraparound)
Assigner
GitHub_M CNA under the mitre root
CNA scorecard C 72/100 over 7749 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
RIOT-OS RIOT Affected: < 2026.07
guessed Create a notification for this product.
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          "value": "RIOT is an open-source microcontroller operating system designed for Internet of Things devices and other embedded systems. Prior to 2026.07, _parse_reply() in sys/net/application_layer/dhcpv6/client.c omits minimum-length validation before passing IA_PD and IA_NA option bodies to sub-option parsers. A malicious or compromised DHCPv6 server can send a REPLY with an option length smaller than the required structure while MODULE_DHCPV6_CLIENT_IA_PD is enabled, causing _parse_ia_pd_option to read past the option body, size_t underflow, and unbounded out-of-bounds heap reads that can crash the device and may expose or corrupt memory. This issue is fixed in version 2026.07."
        }
      ],
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            "baseScore": 9.8,
            "baseSeverity": "CRITICAL",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
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            }
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      "providerMetadata": {
        "dateUpdated": "2026-10-16T16:50:58.750Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
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          "name": "https://github.com/RIOT-OS/RIOT/security/advisories/GHSA-p3fx-9qcg-jmcf",
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          "url": "https://github.com/RIOT-OS/RIOT/security/advisories/GHSA-p3fx-9qcg-jmcf"
        },
        {
          "name": "https://github.com/RIOT-OS/RIOT/pull/22322",
          "tags": [
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          "url": "https://github.com/RIOT-OS/RIOT/pull/22322"
        },
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          "name": "https://github.com/RIOT-OS/RIOT/commit/c9830dc5f2a9bf97418de4fc7d7167d00a45df17",
          "tags": [
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        {
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          "tags": [
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        }
      ],
      "source": {
        "advisory": "GHSA-p3fx-9qcg-jmcf",
        "discovery": "UNKNOWN"
      },
      "title": "RIOT: DHCPv6 client _parse_reply() missing sub-option length check leads to size_t underflow and unbounded OOB heap read"
    }
  },
  "cveMetadata": {
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    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-49868",
    "datePublished": "2026-10-16T16:50:58.750Z",
    "dateReserved": "2026-06-01T22:03:19.641Z",
    "dateUpdated": "2026-10-16T16:50:58.750Z",
    "state": "PUBLISHED"
  },
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  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
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      "date": "2026-10-17",
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      "percentile": "0.29506"
    },
    "nvd": {
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              {
                "product": "RIOT",
                "vendor": "RIOT-OS",
                "versions": [
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                    "version": "\u003c 2026.07"
                  }
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        "descriptions": [
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            "value": "RIOT is an open-source microcontroller operating system designed for Internet of Things devices and other embedded systems. Prior to 2026.07, _parse_reply() in sys/net/application_layer/dhcpv6/client.c omits minimum-length validation before passing IA_PD and IA_NA option bodies to sub-option parsers. A malicious or compromised DHCPv6 server can send a REPLY with an option length smaller than the required structure while MODULE_DHCPV6_CLIENT_IA_PD is enabled, causing _parse_ia_pd_option to read past the option body, size_t underflow, and unbounded out-of-bounds heap reads that can crash the device and may expose or corrupt memory. This issue is fixed in version 2026.07."
          }
        ],
        "id": "CVE-2026-49868",
        "lastModified": "2026-10-16T20:04:29.760",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "HIGH",
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                "confidentialityImpact": "HIGH",
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                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
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        "published": "2026-10-16T17:17:34.963",
        "references": [
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            "source": "security-advisories@github.com",
            "url": "https://github.com/RIOT-OS/RIOT/commit/c9830dc5f2a9bf97418de4fc7d7167d00a45df17"
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          }
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        "vulnStatus": "Deferred",
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                "value": "CWE-125"
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            ],
            "source": "security-advisories@github.com",
            "type": "Primary"
          }
        ]
      }
    }
  }
}



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