Vulnerability-Lookup

CVE-2026-68904 (GCVE-0-2026-68904)

Vulnerability from cvelistv5 – Published: 2026-09-16 16:18 – Updated: 2026-09-16 18:34

Title

node-opcua: TCP Socket Leak (FIN-WAIT-2) via keepalive reconnection cycle - Resource Exhaustion

Summary

node-opcua is an OPC UA implementation for TypeScript and Node.js. From 2.0.0 until 2.170.0, node-opcua clients using the default keepSessionAlive setting can enter a repeated reconnection cycle when an OPC UA server's clock skew causes BadInvalidTimestamp responses. ClientSessionKeepAliveManager._ping_server treated the server-originated ServiceFault as a network outage and forced a transport reconnect, while ClientTCP_transport._on_ACK_response used socket.end() after failed HEL/ACK negotiation and could leave the connection in FIN-WAIT-2 when the peer did not close. Repetition at the keepAliveInterval accumulates file descriptors and memory until the client process or container can be terminated by resource exhaustion. This issue is fixed in version 2.170.0.

Severity

7 (High)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-16 18:18 UTC

CWE

CWE-400 - Uncontrolled Resource Consumption

Assigner

GitHub_M mitre root

References

7 references

URL	Tags
https://github.com/node-opcua/node-opcua/security…	x_refsource_CONFIRM
https://github.com/node-opcua/node-opcua/pull/1497	x_refsource_MISC
https://github.com/node-opcua/node-opcua/commit/1…	x_refsource_MISC
https://github.com/node-opcua/node-opcua/commit/4…	x_refsource_MISC
https://github.com/node-opcua/node-opcua/commit/4…	x_refsource_MISC
https://github.com/node-opcua/node-opcua/commit/d…	x_refsource_MISC
https://github.com/node-opcua/node-opcua/releases…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version	CPE status
node-opcua	node-opcua	Affected: >= 2.0.0, < 2.170.0	guessed

Show details on NVD website

JSON

To clipboard

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FKIE_CVE-2026-68904

Vulnerability from fkie_nvd - Published: 2026-09-16 17:18 - Updated: 2026-09-16 19:17

Severity

7.0 (High) - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H

Summary

References

	URL	Tags
	security-advisories@github.com	https://github.com/node-opcua/node-opcua/commit/1959cbb8946b386d2e24a1cce05b7148099d36e7
	security-advisories@github.com	https://github.com/node-opcua/node-opcua/commit/481664fa6ba8204737c5a92797ff68c3ae780c1c
	security-advisories@github.com	https://github.com/node-opcua/node-opcua/commit/4d59197e2dbd82791d7f36dad7da178715e0c27a
	security-advisories@github.com	https://github.com/node-opcua/node-opcua/commit/dc406fd2d364aa69dd173be21ed32a7ff425017a
	security-advisories@github.com	https://github.com/node-opcua/node-opcua/pull/1497
	security-advisories@github.com	https://github.com/node-opcua/node-opcua/releases/tag/v2.170.0
	security-advisories@github.com	https://github.com/node-opcua/node-opcua/security/advisories/GHSA-r2pf-9cw4-5j65

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "node-opcua",
          "vendor": "node-opcua",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 2.0.0, \u003c 2.170.0"
            }
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        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "node-opcua is an OPC UA implementation for TypeScript and Node.js. From 2.0.0 until 2.170.0, node-opcua clients using the default keepSessionAlive setting can enter a repeated reconnection cycle when an OPC UA server\u0027s clock skew causes BadInvalidTimestamp responses. ClientSessionKeepAliveManager._ping_server treated the server-originated ServiceFault as a network outage and forced a transport reconnect, while ClientTCP_transport._on_ACK_response used socket.end() after failed HEL/ACK negotiation and could leave the connection in FIN-WAIT-2 when the peer did not close. Repetition at the keepAliveInterval accumulates file descriptors and memory until the client process or container can be terminated by resource exhaustion. This issue is fixed in version 2.170.0."
    }
  ],
  "id": "CVE-2026-68904",
  "lastModified": "2026-09-16T19:17:25.403",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 7.0,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "LOW",
          "integrityImpact": "LOW",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H",
          "version": "3.1"
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        "impactScore": 4.7,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
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      "url": "https://github.com/node-opcua/node-opcua/commit/481664fa6ba8204737c5a92797ff68c3ae780c1c"
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      "url": "https://github.com/node-opcua/node-opcua/commit/4d59197e2dbd82791d7f36dad7da178715e0c27a"
    },
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      "source": "security-advisories@github.com",
      "url": "https://github.com/node-opcua/node-opcua/commit/dc406fd2d364aa69dd173be21ed32a7ff425017a"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/node-opcua/node-opcua/pull/1497"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/node-opcua/node-opcua/releases/tag/v2.170.0"
    },
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      "source": "security-advisories@github.com",
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    }
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      "type": "Secondary"
    }
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}

GHSA-R2PF-9CW4-5J65

Vulnerability from github – Published: 2026-09-16 16:19 – Updated: 2026-09-16 16:19

Summary

node-opcua: TCP Socket Leak (FIN-WAIT-2) via keepalive reconnection cycle - Resource Exhaustion

Details

SUMMARY

A combination of bugs in node-opcua causes unlimited TCP socket accumulation (FIN-WAIT-2 state) during automatic reconnection, leading to memory exhaustion and eventual container/process crash (OOM kill). The issue is triggered by the default configuration (keepSessionAlive: true) when the OPC UA server has clock skew relative to the client.

Affected version: Tested on 2.169.0 (latest as of April 2026).

ENVIRONMENT

Node.js: v24.11.0
node-opcua: 2.169.0
OS: Linux (containerized via Podman, slirp4netns networking)
OPC UA Server: Industrial PLC (opc.tcp endpoint), clock skew of ~50 minutes ahead of client
Client config: keepSessionAlive: true (default), keepAliveInterval: 3000, securityMode: None, securityPolicy: None

ROOT CAUSE ANALYSIS

Bug #1 - ClientTCP_transport._on_ACK_response() uses socket.end() instead of socket.destroy()

File: node-opcua-transport/src/client_tcp_transport.ts, _on_ACK_response() method

When the HEL/ACK handshake fails during a reconnection attempt, the error handler calls socket.end():

if (err || !data) {
    externalCallback(err || new Error("no data"));
    if (this._socket) {
        this._socket.end();   // <- sends TCP FIN, leaves socket in FIN-WAIT-2
    }
}

socket.end() sends a TCP FIN and waits for the peer to close its side. If the peer doesn't respond (common with PLCs), the socket remains in FIN-WAIT-2 state indefinitely, leaking file descriptors and memory. During rapid reconnection cycles (triggered by Bug #2 below), every failed HEL/ACK creates a new leaked socket.

Bug #2 - ClientSessionKeepAliveManager._ping_server() treats BadInvalidTimestamp as network outage

File: node-opcua-client/src/client_session_keepalive_manager.ts, _ping_server() method

The keepalive manager reads Server.ServerStatus.CurrentTime on each ping cycle. If the server responds with BadInvalidTimestamp (because the client's RequestHeader.timestamp falls outside the server's tolerance window due to clock skew), the manager treats this as a fatal network error:

// Any error -> emit("failure") -> terminateConnection() -> forceConnectionBreak()

This triggers a full transport-level reconnection on every keepalive cycle (every keepAliveInterval ms). Combined with Bug #1, each reconnection attempt leaks one TCP socket in FIN-WAIT-2. Impact amplification: With keepAliveInterval: 3000 (3 seconds), the client leaks ~20 sockets/minute, ~1200/hour, exhausting resources in hours.

REPRODUCTION STEPS

Set up an OPC UA server with a clock skewed more than the server's timestamp tolerance ahead of the client.
Connect using node-opcua with default settings (keepSessionAlive: true).
Monitor TCP sockets: ss -antp | grep FIN-WAIT-2 | wc -l
Observe FIN-WAIT-2 count growing continuously (approximately one per keepalive interval).
Eventually the process runs out of file descriptors or memory and crashes.

SUGGESTED FIXES

For Bug #1 (_on_ACK_response):

// Replace socket.end() with socket.destroy()
if (this._socket) {
    this._socket.destroy();
}

For Bug #2 (_ping_server): Distinguish between transport-level errors (actual network outage) and application-level OPC UA status codes like BadInvalidTimestamp. The latter indicates the server is reachable and the session is alive - only the timestamp validation failed. The keepalive should not trigger reconnection.

REPORTER

Marco Velluso @Velluso velluso.marco64@gmail.com Requesting CVE assignment and credit as reporter upon fix publication.

Severity

7.0 (High)


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

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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "node-opcua-transport"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.0.0"
            },
            {
              "fixed": "2.170.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "node-opcua-client"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.0.0"
            },
            {
              "fixed": "2.170.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "node-opcua"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.0.0"
            },
            {
              "fixed": "2.170.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-68904"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-400"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-09-16T16:19:21Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "SUMMARY\n-------\nA combination of bugs in node-opcua causes unlimited TCP socket accumulation (FIN-WAIT-2 state) during automatic reconnection, leading to memory exhaustion and eventual container/process crash (OOM kill). The issue is triggered by the default configuration (keepSessionAlive: true) when the OPC UA server has clock skew relative to the client.\n\nAffected version: Tested on 2.169.0 (latest as of April 2026).\n\nENVIRONMENT\n-----------\n- Node.js: v24.11.0\n- node-opcua: 2.169.0\n- OS: Linux (containerized via Podman, slirp4netns networking)\n- OPC UA Server: Industrial PLC (opc.tcp endpoint), clock skew of ~50 minutes ahead of client\n- Client config: keepSessionAlive: true (default), keepAliveInterval: 3000, securityMode: None, securityPolicy: None\n\nROOT CAUSE ANALYSIS\n-------------------\n\nBug #1 - ClientTCP_transport._on_ACK_response() uses socket.end() instead of socket.destroy()\n\nFile: node-opcua-transport/src/client_tcp_transport.ts, _on_ACK_response() method\n\nWhen the HEL/ACK handshake fails during a reconnection attempt, the error handler calls socket.end():\n\n    if (err || !data) {\n        externalCallback(err || new Error(\"no data\"));\n        if (this._socket) {\n            this._socket.end();   // \u003c- sends TCP FIN, leaves socket in FIN-WAIT-2\n        }\n    }\n\nsocket.end() sends a TCP FIN and waits for the peer to close its side. If the peer doesn\u0027t respond (common with PLCs), the socket remains in FIN-WAIT-2 state indefinitely, leaking file descriptors and memory.\nDuring rapid reconnection cycles (triggered by Bug #2 below), every failed HEL/ACK creates a new leaked socket.\n\n---\n\nBug #2 - ClientSessionKeepAliveManager._ping_server() treats BadInvalidTimestamp as network outage\n\nFile: node-opcua-client/src/client_session_keepalive_manager.ts, _ping_server() method\n\nThe keepalive manager reads Server.ServerStatus.CurrentTime on each ping cycle. If the server responds with BadInvalidTimestamp (because the client\u0027s RequestHeader.timestamp falls outside the server\u0027s tolerance window due to clock skew), the manager treats this as a fatal network error:\n\n    // Any error -\u003e emit(\"failure\") -\u003e terminateConnection() -\u003e forceConnectionBreak()\n\nThis triggers a full transport-level reconnection on every keepalive cycle (every keepAliveInterval ms). Combined with Bug #1, each reconnection attempt leaks one TCP socket in FIN-WAIT-2.\nImpact amplification: With keepAliveInterval: 3000 (3 seconds), the client leaks ~20 sockets/minute, ~1200/hour, exhausting resources in hours.\n\nREPRODUCTION STEPS\n------------------\n1. Set up an OPC UA server with a clock skewed more than the server\u0027s timestamp tolerance ahead of the client.\n2. Connect using node-opcua with default settings (keepSessionAlive: true).\n3. Monitor TCP sockets: ss -antp | grep FIN-WAIT-2 | wc -l\n4. Observe FIN-WAIT-2 count growing continuously (approximately one per keepalive interval).\n5. Eventually the process runs out of file descriptors or memory and crashes.\n\nSUGGESTED FIXES\n---------------\n\nFor Bug #1 (_on_ACK_response):\n\n    // Replace socket.end() with socket.destroy()\n    if (this._socket) {\n        this._socket.destroy();\n    }\n\nFor Bug #2 (_ping_server):\nDistinguish between transport-level errors (actual network outage) and application-level OPC UA status codes like BadInvalidTimestamp. The latter indicates the server is reachable and the session is alive - only the timestamp validation failed. The keepalive should not trigger reconnection.\n\nREPORTER\n--------\nMarco Velluso @Velluso\n[velluso.marco64@gmail.com](mailto:velluso.marco64@gmail.com)\nRequesting CVE assignment and credit as reporter upon fix publication.",
  "id": "GHSA-r2pf-9cw4-5j65",
  "modified": "2026-09-16T16:19:21Z",
  "published": "2026-09-16T16:19:21Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/node-opcua/node-opcua/security/advisories/GHSA-r2pf-9cw4-5j65"
    },
    {
      "type": "WEB",
      "url": "https://github.com/node-opcua/node-opcua/pull/1497"
    },
    {
      "type": "WEB",
      "url": "https://github.com/node-opcua/node-opcua/commit/1959cbb8946b386d2e24a1cce05b7148099d36e7"
    },
    {
      "type": "WEB",
      "url": "https://github.com/node-opcua/node-opcua/commit/481664fa6ba8204737c5a92797ff68c3ae780c1c"
    },
    {
      "type": "WEB",
      "url": "https://github.com/node-opcua/node-opcua/commit/4d59197e2dbd82791d7f36dad7da178715e0c27a"
    },
    {
      "type": "WEB",
      "url": "https://github.com/node-opcua/node-opcua/commit/dc406fd2d364aa69dd173be21ed32a7ff425017a"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/node-opcua/node-opcua"
    },
    {
      "type": "WEB",
      "url": "https://github.com/node-opcua/node-opcua/releases/tag/v2.170.0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "node-opcua: TCP Socket Leak (FIN-WAIT-2) via keepalive reconnection cycle - Resource Exhaustion"
}

Sightings

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Detection rules are retrieved from Rulezet.

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.
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Action not permitted

CVE-2026-68904 (GCVE-0-2026-68904)

FKIE_CVE-2026-68904

GHSA-R2PF-9CW4-5J65

SUMMARY

ENVIRONMENT

ROOT CAUSE ANALYSIS

REPRODUCTION STEPS

SUGGESTED FIXES

REPORTER

Tags

Sightings

Nomenclature

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