Vulnerability-Lookup

GHSA-RW53-R2P7-QGMF

Vulnerability from github – Published: 2026-09-29 18:32 – Updated: 2026-09-29 18:32

Details

A DHCP server, or anyone on the LAN who answers a DISCOVER first, can make the client read about a

kilobyte past the end of the received message.

The option walk keeps a pointer and an offset in step, and the only bound check uses the offset:




/* addons/dhcp/nxd_dhcp_client.c:7538, 7572 */



while (i < length - 1)



{

    ...
    size = *(++data);      /* data moves 1: type -> length byte */
    data += size + 1;      /* data moves size + 1 more          */
    i += size + 1;         /* i moves only size + 1             */


}

A TLV option occupies size + 2 bytes. data is advanced by size + 2 in total, i by size + 1, so

the offset falls one byte behind the real read position for every option the walk skips. After

enough skipped options the check i < length - 1 still holds while data is already past the end

of the message, and the subsequent read of the type and length bytes comes from whatever follows.

A single OFFER carrying a long run of skippable options is enough:




ERROR: AddressSanitizer: heap-buffer-overflow



READ of size 1 at 0x61b000000794 thread T5

    #0 _nx_dhcp_search_buffer     addons/dhcp/nxd_dhcp_client.c:7541
    #1 _nx_dhcp_get_option_value  addons/dhcp/nxd_dhcp_client.c:7082


0x61b000000794 is located 164 bytes to the right of 1648-byte region

A well formed OFFER through the same path is handled normally, the client records the offer and

moves to REQUESTING, so the difference is the option layout rather than the harness.

The read runs in the DHCP client thread while the client is still unconfigured, so it happens on

every boot in reach of a hostile DHCP responder. The values read are used to configure the

interface, which is how the disclosed bytes become observable.

Advance i by size + 2, or derive the bound from data rather than keeping a second counter.

Severity

5.3 (Medium)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-102720"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-125"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-29T18:17:11Z",
    "severity": "MODERATE"
  },
  "details": "A DHCP server, or anyone on the LAN who answers a DISCOVER first, can make the client read about a\n\n\n\nkilobyte past the end of the received message.\n\n\n\nThe option walk keeps a pointer and an offset in step, and the only bound check uses the offset:\n\n\n\n```c\n\n\n\n/* addons/dhcp/nxd_dhcp_client.c:7538, 7572 */\n\n\n\nwhile (i \u003c length - 1)\n\n\n\n{\n\n    ...\n    size = *(++data);      /* data moves 1: type -\u003e length byte */\n    data += size + 1;      /* data moves size + 1 more          */\n    i += size + 1;         /* i moves only size + 1             */\n\n\n}\n\n\n\n```\n\n\n\nA TLV option occupies size + 2 bytes. `data` is advanced by size + 2 in total, `i` by size + 1, so\n\n\n\nthe offset falls one byte behind the real read position for every option the walk skips. After\n\n\n\nenough skipped options the check `i \u003c length - 1` still holds while `data` is already past the end\n\n\n\nof the message, and the subsequent read of the type and length bytes comes from whatever follows.\n\n\n\nA single OFFER carrying a long run of skippable options is enough:\n\n\n\n```\n\n\n\nERROR: AddressSanitizer: heap-buffer-overflow\n\n\n\nREAD of size 1 at 0x61b000000794 thread T5\n\n    #0 _nx_dhcp_search_buffer     addons/dhcp/nxd_dhcp_client.c:7541\n    #1 _nx_dhcp_get_option_value  addons/dhcp/nxd_dhcp_client.c:7082\n\n\n0x61b000000794 is located 164 bytes to the right of 1648-byte region\n\n\n\n```\n\n\n\nA well formed OFFER through the same path is handled normally, the client records the offer and\n\n\n\nmoves to REQUESTING, so the difference is the option layout rather than the harness.\n\n\n\nThe read runs in the DHCP client thread while the client is still unconfigured, so it happens on\n\n\n\nevery boot in reach of a hostile DHCP responder. The values read are used to configure the\n\n\n\ninterface, which is how the disclosed bytes become observable.\n\n\n\nAdvance `i` by size + 2, or derive the bound from `data` rather than keeping a second counter.",
  "id": "GHSA-rw53-r2p7-qgmf",
  "modified": "2026-09-29T18:32:01Z",
  "published": "2026-09-29T18:32:01Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/eclipse-threadx/netxduo/security/advisories/GHSA-8hj5-p46x-5h28"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-102720"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/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-2026-102720 (GCVE-0-2026-102720)

Vulnerability from cvelistv5 – Published: 2026-09-29 17:46 – Updated: 2026-09-29 18:37

Summary

A DHCP server, or anyone on the LAN who answers a DISCOVER first, can make the client read about a kilobyte past the end of the received message. The option walk keeps a pointer and an offset in step, and the only bound check uses the offset: ```c /* addons/dhcp/nxd_dhcp_client.c:7538, 7572 */ while (i < length - 1) { ... size = *(++data); /* data moves 1: type -> length byte */ data += size + 1; /* data moves size + 1 more */ i += size + 1; /* i moves only size + 1 */ } ``` A TLV option occupies size + 2 bytes. `data` is advanced by size + 2 in total, `i` by size + 1, so the offset falls one byte behind the real read position for every option the walk skips. After enough skipped options the check `i < length - 1` still holds while `data` is already past the end of the message, and the subsequent read of the type and length bytes comes from whatever follows. A single OFFER carrying a long run of skippable options is enough: ``` ERROR: AddressSanitizer: heap-buffer-overflow READ of size 1 at 0x61b000000794 thread T5 #0 _nx_dhcp_search_buffer addons/dhcp/nxd_dhcp_client.c:7541 #1 _nx_dhcp_get_option_value addons/dhcp/nxd_dhcp_client.c:7082 0x61b000000794 is located 164 bytes to the right of 1648-byte region ``` A well formed OFFER through the same path is handled normally, the client records the offer and moves to REQUESTING, so the difference is the option layout rather than the harness. The read runs in the DHCP client thread while the client is still unconfigured, so it happens on every boot in reach of a hostile DHCP responder. The values read are used to configure the interface, which is how the disclosed bytes become observable. Advance `i` by size + 2, or derive the bound from `data` rather than keeping a second counter.

Severity

5.3 (Medium)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-29 18:36 UTC

CWE

CWE-125 - Out-of-bounds Read

Assigner

eclipse mitre root Scorecard

References

1 reference

URL	Tags
https://github.com/eclipse-threadx/netxduo/securi…

Impacted products

1 product

Vendor	Product	Version
Eclipse Foundation	eclipse-threadx/netxduo	Affected: 0 , ≤ 6.5.1 (semver)

Credits

L0stHeart

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-102720",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-29T18:36:33.534376Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-09-29T18:37:07.341Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "eclipse-threadx/netxduo",
          "vendor": "Eclipse Foundation",
          "versions": [
            {
              "lessThanOrEqual": "6.5.1",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "reporter",
          "value": "L0stHeart"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
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              "base64": false,
              "type": "text/html",
              "value": "\u003cp\u003eA DHCP server, or anyone on the LAN who answers a DISCOVER first, can make the client read about a\u003c/p\u003e\u003cp\u003ekilobyte past the end of the received message.\u003c/p\u003e\u003cp\u003eThe option walk keeps a pointer and an offset in step, and the only bound check uses the offset:\u003c/p\u003e\u003cp\u003e```c\u003c/p\u003e\u003cp\u003e/* addons/dhcp/nxd_dhcp_client.c:7538, 7572 */\u003c/p\u003e\u003cp\u003ewhile (i \u0026lt; length - 1)\u003c/p\u003e\u003cp\u003e{\u003c/p\u003e\u003ccode\u003e    ...\u003c/code\u003e\u003cbr\u003e\u003ccode\u003e    size = *(++data);      /* data moves 1: type -\u0026gt; length byte */\u003c/code\u003e\u003cbr\u003e\u003ccode\u003e    data += size + 1;      /* data moves size + 1 more          */\u003c/code\u003e\u003cbr\u003e\u003ccode\u003e    i += size + 1;         /* i moves only size + 1             */\u003c/code\u003e\u003cbr\u003e\u003cp\u003e}\u003c/p\u003e\u003cp\u003e```\u003c/p\u003e\u003cp\u003eA TLV option occupies size + 2 bytes. `data` is advanced by size + 2 in total, `i` by size + 1, so\u003c/p\u003e\u003cp\u003ethe offset falls one byte behind the real read position for every option the walk skips. After\u003c/p\u003e\u003cp\u003eenough skipped options the check `i \u0026lt; length - 1` still holds while `data` is already past the end\u003c/p\u003e\u003cp\u003eof the message, and the subsequent read of the type and length bytes comes from whatever follows.\u003c/p\u003e\u003cp\u003eA single OFFER carrying a long run of skippable options is enough:\u003c/p\u003e\u003cp\u003e```\u003c/p\u003e\u003cp\u003eERROR: AddressSanitizer: heap-buffer-overflow\u003c/p\u003e\u003cp\u003eREAD of size 1 at 0x61b000000794 thread T5\u003c/p\u003e\u003ccode\u003e    #0 _nx_dhcp_search_buffer     addons/dhcp/nxd_dhcp_client.c:7541\u003c/code\u003e\u003cbr\u003e\u003ccode\u003e    #1 _nx_dhcp_get_option_value  addons/dhcp/nxd_dhcp_client.c:7082\u003c/code\u003e\u003cbr\u003e\u003cp\u003e0x61b000000794 is located 164 bytes to the right of 1648-byte region\u003c/p\u003e\u003cp\u003e```\u003c/p\u003e\u003cp\u003eA well formed OFFER through the same path is handled normally, the client records the offer and\u003c/p\u003e\u003cp\u003emoves to REQUESTING, so the difference is the option layout rather than the harness.\u003c/p\u003e\u003cp\u003eThe read runs in the DHCP client thread while the client is still unconfigured, so it happens on\u003c/p\u003e\u003cp\u003eevery boot in reach of a hostile DHCP responder. The values read are used to configure the\u003c/p\u003e\u003cp\u003einterface, which is how the disclosed bytes become observable.\u003c/p\u003e\u003cp\u003eAdvance `i` by size + 2, or derive the bound from `data` rather than keeping a second counter.\u003c/p\u003e"
            }
          ],
          "value": "A DHCP server, or anyone on the LAN who answers a DISCOVER first, can make the client read about a\n\n\n\nkilobyte past the end of the received message.\n\n\n\nThe option walk keeps a pointer and an offset in step, and the only bound check uses the offset:\n\n\n\n```c\n\n\n\n/* addons/dhcp/nxd_dhcp_client.c:7538, 7572 */\n\n\n\nwhile (i \u003c length - 1)\n\n\n\n{\n\n    ...\n    size = *(++data);      /* data moves 1: type -\u003e length byte */\n    data += size + 1;      /* data moves size + 1 more          */\n    i += size + 1;         /* i moves only size + 1             */\n\n\n}\n\n\n\n```\n\n\n\nA TLV option occupies size + 2 bytes. `data` is advanced by size + 2 in total, `i` by size + 1, so\n\n\n\nthe offset falls one byte behind the real read position for every option the walk skips. After\n\n\n\nenough skipped options the check `i \u003c length - 1` still holds while `data` is already past the end\n\n\n\nof the message, and the subsequent read of the type and length bytes comes from whatever follows.\n\n\n\nA single OFFER carrying a long run of skippable options is enough:\n\n\n\n```\n\n\n\nERROR: AddressSanitizer: heap-buffer-overflow\n\n\n\nREAD of size 1 at 0x61b000000794 thread T5\n\n    #0 _nx_dhcp_search_buffer     addons/dhcp/nxd_dhcp_client.c:7541\n    #1 _nx_dhcp_get_option_value  addons/dhcp/nxd_dhcp_client.c:7082\n\n\n0x61b000000794 is located 164 bytes to the right of 1648-byte region\n\n\n\n```\n\n\n\nA well formed OFFER through the same path is handled normally, the client records the offer and\n\n\n\nmoves to REQUESTING, so the difference is the option layout rather than the harness.\n\n\n\nThe read runs in the DHCP client thread while the client is still unconfigured, so it happens on\n\n\n\nevery boot in reach of a hostile DHCP responder. The values read are used to configure the\n\n\n\ninterface, which is how the disclosed bytes become observable.\n\n\n\nAdvance `i` by size + 2, or derive the bound from `data` rather than keeping a second counter."
        }
      ],
      "metrics": [
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            "attackRequirements": "NONE",
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            "version": "4.0",
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            "vulnConfidentialityImpact": "LOW",
            "vulnIntegrityImpact": "NONE",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
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          "format": "CVSS",
          "scenarios": [
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              "lang": "en",
              "value": "GENERAL"
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          "descriptions": [
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              "description": "CWE-125 Out-of-bounds Read",
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              "type": "CWE"
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          "url": "https://github.com/eclipse-threadx/netxduo/security/advisories/GHSA-8hj5-p46x-5h28"
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    "datePublished": "2026-09-29T17:46:23.228Z",
    "dateReserved": "2026-09-29T16:15:16.300Z",
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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.

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.

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GHSA-RW53-R2P7-QGMF

CVE-2026-102720 (GCVE-0-2026-102720)

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