Vulnerability-Lookup

GHSA-3X22-R5W3-J249

Vulnerability from github – Published: 2026-07-18 15:31 – Updated: 2026-07-18 15:31

Details

OpenPLC_v3 contains a heap-based buffer overflow in the getData() function in webserver/core/modbus_master.cpp. getData() reads characters between two delimiters into a caller-supplied buffer with no size parameter and no bounds check. In parseConfig() the function is invoked with the 100-byte heap-allocated MB_device.dev_name field. An authenticated attacker with access to the OpenPLC web interface can send a crafted HTTP POST to the /modbus endpoint with an oversized device_name value; the value is persisted to mbconfig.cfg and parsed on load, overflowing dev_name and overwriting adjacent struct fields (protocol at offset 108, dev_address at offset 109, ip_port at offset 210). A 200-byte payload writes 100 bytes past the allocation. The result is heap corruption leading to runtime crash and denial of service of the PLC process control loop, with attacker-controlled overwrite of adjacent configuration fields. The upstream repository was archived on 2026-04-04 and no fix is expected; the vendor has confirmed the issue does not affect OpenPLC Runtime v4.

Severity

8.8 (High)


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

8.7 (High)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-11826"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-122"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-18T14:17:11Z",
    "severity": "HIGH"
  },
  "details": "OpenPLC_v3 contains a heap-based buffer overflow in the getData() function in webserver/core/modbus_master.cpp. getData() reads characters between two delimiters into a caller-supplied buffer with no size parameter and no bounds check. In parseConfig() the function is invoked with the 100-byte heap-allocated MB_device.dev_name field. An authenticated attacker with access to the OpenPLC web interface can send a crafted HTTP POST to the /modbus endpoint with an oversized device_name value; the value is persisted to mbconfig.cfg and parsed on load, overflowing dev_name and overwriting adjacent struct fields (protocol at offset 108, dev_address at offset 109, ip_port at offset 210). A 200-byte payload writes 100 bytes past the allocation. The result is heap corruption leading to runtime crash and denial of service of the PLC process control loop, with attacker-controlled overwrite of adjacent configuration fields. The upstream repository was archived on 2026-04-04 and no fix is expected; the vendor has confirmed the issue does not affect OpenPLC Runtime v4.",
  "id": "GHSA-3x22-r5w3-j249",
  "modified": "2026-07-18T15:31:50Z",
  "published": "2026-07-18T15:31:50Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-11826"
    },
    {
      "type": "WEB",
      "url": "https://github.com/thiagoralves/OpenPLC_v3/commit/b4702061dc14d1024856f71b4543298d77007b88"
    },
    {
      "type": "WEB",
      "url": "https://gist.github.com/Shukhrat-03/5cf1825b72e485ef98a32958dfbc611a#security-vulnerability-report"
    },
    {
      "type": "WEB",
      "url": "https://github.com/thiagoralves/OpenPLC_v3"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/openplc-v3-heap-based-buffer-overflow-in-modbus-master-getdata"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/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-2026-11826 (GCVE-0-2026-11826)

Vulnerability from cvelistv5 – Published: 2026-07-18 13:35 – Updated: 2026-07-18 13:35

Title

OpenPLC_v3 Heap-Based Buffer Overflow in Modbus Master getData()

Summary

Severity

8.7 (High)


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

8.8 (High)


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

CWE

CWE-122 - Heap-based Buffer Overflow

Assigner

VulnCheck

References

4 references

URL	Tags
https://gist.github.com/Shukhrat-03/5cf1825b72e48…	technical-description
https://github.com/thiagoralves/OpenPLC_v3/commit…	issue-tracking
https://github.com/thiagoralves/OpenPLC_v3	product
https://www.vulncheck.com/advisories/openplc-v3-h…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
openplcproject	OpenPLC_v3	Affected: 0 , ≤ b470206 (git)

Date Public

2026-07-17 00:00

Credits

Shuhratbek Uraimov Shuhratbek Uraimov

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "affected",
          "product": "OpenPLC_v3",
          "vendor": "openplcproject",
          "versions": [
            {
              "lessThanOrEqual": "b470206",
              "status": "affected",
              "version": "0",
              "versionType": "git"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Shuhratbek Uraimov"
        },
        {
          "lang": "en",
          "type": "reporter",
          "value": "Shuhratbek Uraimov"
        }
      ],
      "datePublic": "2026-07-17T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "OpenPLC_v3 contains a heap-based buffer overflow in the getData() function in webserver/core/modbus_master.cpp. getData() reads characters between two delimiters into a caller-supplied buffer with no size parameter and no bounds check. In parseConfig() the function is invoked with the 100-byte heap-allocated MB_device.dev_name field. An authenticated attacker with access to the OpenPLC web interface can send a crafted HTTP POST to the /modbus endpoint with an oversized device_name value; the value is persisted to mbconfig.cfg and parsed on load, overflowing dev_name and overwriting adjacent struct fields (protocol at offset 108, dev_address at offset 109, ip_port at offset 210). A 200-byte payload writes 100 bytes past the allocation. The result is heap corruption leading to runtime crash and denial of service of the PLC process control loop, with attacker-controlled overwrite of adjacent configuration fields. The upstream repository was archived on 2026-04-04 and no fix is expected; the vendor has confirmed the issue does not affect OpenPLC Runtime v4."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 8.7,
            "baseSeverity": "HIGH",
            "exploitMaturity": "NOT_DEFINED",
            "privilegesRequired": "LOW",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        },
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 8.8,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-122",
              "description": "Heap-based Buffer Overflow",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-18T13:35:35.639Z",
        "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
        "shortName": "VulnCheck"
      },
      "references": [
        {
          "name": "GitHub Gist",
          "tags": [
            "technical-description"
          ],
          "url": "https://gist.github.com/Shukhrat-03/5cf1825b72e485ef98a32958dfbc611a#security-vulnerability-report"
        },
        {
          "name": "Patch Commit",
          "tags": [
            "issue-tracking"
          ],
          "url": "https://github.com/thiagoralves/OpenPLC_v3/commit/b4702061dc14d1024856f71b4543298d77007b88"
        },
        {
          "name": "Product",
          "tags": [
            "product"
          ],
          "url": "https://github.com/thiagoralves/OpenPLC_v3"
        },
        {
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://www.vulncheck.com/advisories/openplc-v3-heap-based-buffer-overflow-in-modbus-master-getdata"
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "OpenPLC_v3 Heap-Based Buffer Overflow in Modbus Master getData()",
      "x_generator": {
        "engine": "vulncheck"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
    "assignerShortName": "VulnCheck",
    "cveId": "CVE-2026-11826",
    "datePublished": "2026-07-18T13:35:35.639Z",
    "dateReserved": "2026-06-09T19:53:45.722Z",
    "dateUpdated": "2026-07-18T13:35:35.639Z",
    "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-3X22-R5W3-J249

CVE-2026-11826 (GCVE-0-2026-11826)

Tags

Sightings

Nomenclature