CVE-2026-54500

Full vulnerability record from the local CVENow database.

Description

Oj (Optimized JSON) is a JSON parser and Object marshaller packaged as a Ruby gem. In versions prior to 3.17.3, Oj.load in :object mode reads uninitialized stack memory (and, for long keys, reads out of bounds) when parsing a JSON object whose key is 254 bytes or longer. The interned bytes can surface to the caller, disclosing process stack memory. In ext/oj/intern.c, form_attr() handles the long-key path by allocating a heap buffer, `b`, populating it with the attribute name, and then freeing it — but it passed the uninitialized stack buffer buf (not b) to rb_intern3(). rb_intern3 therefore reads len + 1 bytes of uninitialized stack memory. When the key length is >= 256, it also reads out of bounds past the 256-byte buf. The resulting bytes are interned and can reach the caller via the produced Symbol or via the EncodingError message raised on invalid UTF-8, leaking process stack contents. This issue has been fixed in version 3.17.3.

Severity

MEDIUM

CVSS score

5.3 (v3.1)

Vulnerability status

Deferred

Source identifier

[email protected]

Published

2026-07-01 00:16:32.147000

Last modified

2026-10-25 17:10:00.197000

View original CVE JSON

{
  "id": "CVE-2026-54500",
  "sourceIdentifier": "[email protected]",
  "published": "2026-07-01T00:16:32.147",
  "lastModified": "2026-10-25T17:10:00.197",
  "vulnStatus": "Deferred",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Oj (Optimized JSON) is a JSON parser and Object marshaller packaged as a Ruby gem. In versions prior to 3.17.3, Oj.load in :object mode reads uninitialized stack memory (and, for long keys, reads out of bounds) when parsing a JSON object whose key is 254 bytes or longer. The interned bytes can surface to the caller, disclosing process stack memory. In ext/oj/intern.c, form_attr() handles the long-key path by allocating a heap buffer, `b`, populating it with the attribute name, and then freeing it — but it passed the uninitialized stack buffer buf (not b) to rb_intern3(). rb_intern3 therefore reads len + 1 bytes of uninitialized stack memory. When the key length is >= 256, it also reads out of bounds past the 256-byte buf. The resulting bytes are interned and can reach the caller via the produced Symbol or via the EncodingError message raised on invalid UTF-8, leaking process stack contents. This issue has been fixed in version 3.17.3."
    },
    {
      "lang": "es",
      "value": "Oj (Optimized JSON) es un analizador JSON y un serializador de objetos empaquetado como una gema de Ruby. En versiones anteriores a la 3.17.3, Oj.load en modo :object lee memoria de pila no inicializada (y, para claves largas, lee fuera de los límites) al analizar un objeto JSON cuya clave tiene 254 bytes o más. Los bytes internados pueden llegar al llamador, revelando la memoria de pila del proceso. En ext/oj/intern.c, form_attr() maneja la ruta de clave larga asignando un búfer en el heap, ’b’, rellenándolo con el nombre del atributo y luego liberándolo - pero pasó el búfer de pila no inicializado buf (no ’b’) a rb_intern3(). rb_intern3, por lo tanto, lee len + 1 bytes de memoria de pila no inicializada. Cuando la longitud de la clave es >= 256, también lee fuera de los límites más allá del búfer buf de 256 bytes. Los bytes resultantes son internados y pueden llegar al llamador a través del Símbolo producido o a través del mensaje de EncodingError generado por UTF-8 no válido, filtrando el contenido de la pila del proceso. Este problema ha sido solucionado en la versión 3.17.3."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "ohler55",
          "product": "oj",
          "versions": [
            {
              "version": "< 3.17.3",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
          "baseScore": 5.3,
          "baseSeverity": "MEDIUM",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "LOW",
          "integrityImpact": "NONE",
          "availabilityImpact": "NONE"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 1.4
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-07-01T13:34:29.080763Z",
          "id": "CVE-2026-54500",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-125"
        },
        {
          "lang": "en",
          "value": "CWE-908"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/ohler55/oj/security/advisories/GHSA-fm7p-mprw-wjm9",
      "source": "[email protected]"
    }
  ]
}