FKIE_CVE-2026-33592

Vulnerability from fkie_nvd - Published: 2026-07-02 08:16 - Updated: 2026-07-02 17:39
Severity
7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Summary
An unauthenticated remote attacker can exhaust server memory via the FindServers Discovery Service in open62541. The serverUris field of FindServersRequest is not validated for length or array size. An attacker can declare an arbitrarily large string (up to ~3.9 GB) delivered across intermediate chunks without ever sending the final chunk. The server buffers all chunks in RAM indefinitely until the SecureChannel times out. The attack is pre-session and bypasses all encryption configuration. The issue affects open62541: from 1.4.0 through 1.4.16, from 1.5.0 through 1.5.4, master.
References
a6d3dc9e-0591-4a13-bce7-0f5b31ff6158https://github.com/open62541/open62541
a6d3dc9e-0591-4a13-bce7-0f5b31ff6158https://github.com/open62541/open62541/pull/8142
a6d3dc9e-0591-4a13-bce7-0f5b31ff6158https://github.com/open62541/open62541/pull/8142/changes/d253818d6c5e870e1db0e360b18138c8bdc809ae
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "open62541",
          "vendor": "open62541 project / o6 Automation GmbH",
          "versions": [
            {
              "lessThanOrEqual": "1.4.16",
              "status": "affected",
              "version": "1.4.0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "1.5.4",
              "status": "affected",
              "version": "1.5.0",
              "versionType": "semver"
            },
            {
              "status": "affected",
              "version": "master",
              "versionType": "custom"
            }
          ]
        }
      ],
      "source": "a6d3dc9e-0591-4a13-bce7-0f5b31ff6158"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "An unauthenticated remote attacker can exhaust\nserver memory via the FindServers Discovery Service in open62541. The\nserverUris field of FindServersRequest is not validated for length or array\nsize. An attacker can declare an arbitrarily large string (up to ~3.9 GB)\ndelivered across intermediate chunks without ever sending the final chunk. The\nserver buffers all chunks in RAM indefinitely until the SecureChannel times\nout. The attack is pre-session and bypasses all encryption configuration. The\u00a0issue affects open62541: from 1.4.0 through 1.4.16, from 1.5.0 through 1.5.4, master."
    }
  ],
  "id": "CVE-2026-33592",
  "lastModified": "2026-07-02T17:39:07.620",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6,
        "source": "a6d3dc9e-0591-4a13-bce7-0f5b31ff6158",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-33592",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-07-02T12:29:37.308768Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-07-02T08:16:39.230",
  "references": [
    {
      "source": "a6d3dc9e-0591-4a13-bce7-0f5b31ff6158",
      "url": "https://github.com/open62541/open62541"
    },
    {
      "source": "a6d3dc9e-0591-4a13-bce7-0f5b31ff6158",
      "url": "https://github.com/open62541/open62541/pull/8142"
    },
    {
      "source": "a6d3dc9e-0591-4a13-bce7-0f5b31ff6158",
      "url": "https://github.com/open62541/open62541/pull/8142/changes/d253818d6c5e870e1db0e360b18138c8bdc809ae"
    }
  ],
  "sourceIdentifier": "a6d3dc9e-0591-4a13-bce7-0f5b31ff6158",
  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-770"
        },
        {
          "lang": "en",
          "value": "CWE-789"
        }
      ],
      "source": "a6d3dc9e-0591-4a13-bce7-0f5b31ff6158",
      "type": "Secondary"
    }
  ]
}


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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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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.