cJSON 1.7.19 Wrong-Key Modification via JSON Pointer Escape Decoding

{
  "id": "e8f25374de1782dcaaa54d4000e1b897b424e6e0c1fc4c87920524c1f8d865fb",
  "url": "https://osv.dev/vulnerability/CVE-2026-29036",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "cJSON 1.7.19 Wrong-Key Modification via JSON Pointer Escape Decoding",
    "summary": "cJSON versions 1.5.0 through 1.7.19 contain an incorrectly-resolved name or reference vulnerability in the decode_pointer_inplace() function within cJSON_Utils.c that allows unauthenticated attackers to cause JSON Patch operations to target wrong object keys by supplying crafted JSON Pointer escape sequences (~0 or ~1) in patch paths. Attackers can submit malicious RFC 6902 JSON Patch input to applications using cJSONUtils_ApplyPatches() or cJSONUtils_ApplyPatchesCaseSensitive() to silently corrupt data or delete unintended keys, potentially bypassing authorization controls in applications that rely on JSON Patch for access-controlled data modification.",
    "evidence": "osv:CVE-2026-29036",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-29036",
      "aliases": [
        "CVE-2026-29036"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/davegamble/cjson",
              "type": "GIT",
              "events": [
                {
                  "introduced": "1217ca9e9f0134fe4666b3c81771af545c4c1b9d"
                },
                {
                  "last_affected": "c859b25da02955fef659d658b8f324b5cde87be3"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "1.5.0"
                      },
                      {
                        "last_affected": "1.7.19"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  },
                  {
                    "range": [
                      {
                        "introduced": "1.5.0"
                      },
                      {
                        "last_affected": "1.7.19"
                      }
                    ],
                    "source": "DESCRIPTION"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v1.7.19",
            "v1.7.18",
            "v1.7.17",
            "v1.7.16",
            "v1.7.15",
            "v1.7.14",
            "v1.7.13",
            "v1.7.12",
            "v1.7.11",
            "v1.7.10",
            "v1.7.9",
            "v1.7.8",
            "v1.7.7",
            "v1.7.6",
            "v1.7.5",
            "v1.7.4",
            "v1.7.3",
            "v1.7.2",
            "v1.7.1",
            "v1.7.0",
            "v1.6.0",
            "v1.5.9",
            "v1.5.8",
            "v1.5.7",
            "v1.5.6",
            "v1.5.5",
            "v1.5.4",
            "v1.5.3",
            "v1.5.2",
            "v1.5.1",
            "v1.5.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-29036.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:53.307762167Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/29xxx/CVE-2026-29036.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-29036",
        "https://www.vulncheck.com/advisories/cjson-wrong-key-modification-via-json-pointer-escape-decoding",
        "https://github.com/DaveGamble/cJSON"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-706"
        ],
        "cna_assigner": "VulnCheck",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/29xxx/CVE-2026-29036.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-29036",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 522308,
  "published_at": "2026-08-11T21:30:01.779+00:00"
}