CVE-2026-106435

{
  "etk_id": "ETK-2026-2571",
  "cve_id": "CVE-2026-106435",
  "display_id": "CVE-2026-106435",
  "ghsa_id": "GHSA-86gh-39m5-hhg6",
  "euvd_id": "EUVD-2026-95254",
  "status": "published",
  "anchor_state": "anchored",
  "title": "Out-of-bounds read in PyMongo BSON decoding",
  "summary": "PyMongo versions through 4.18.2 can read beyond an input buffer while the C BSON decoder processes malformed BSON regular-expression elements. An attacker able to provide BSON to the application's decode APIs may terminate the process when the C extension is loaded and the input uses a non-NUL-terminated buffer such as an mmap or array.",
  "mitigation": "Upgrade pymongo to version 4.18.3. Until upgrade, decode untrusted BSON only from bytes or bytearray, copying mmap or other non-NUL-terminated inputs first.",
  "vendor": "mongodb",
  "product": "pip:pymongo",
  "affected": [
    {
      "affected_notes": [],
      "affected_ranges": [
        ">= 3.9.0, <= 4.18.2"
      ],
      "ecosystem": "pip",
      "fixed_versions": [
        "4.18.3"
      ],
      "package_name": "pymongo",
      "purl": "pkg:pypi/pymongo"
    }
  ],
  "cwes": [
    125
  ],
  "cvss_score": 8.2,
  "cvss_src": "cna_vendor",
  "cvss_vector": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
  "epss_score": null,
  "epss_percentile": null,
  "epss_asof": null,
  "automation": "contextual",
  "check": false,
  "check_confidence_basis": null,
  "exploit": false,
  "pipeline_minutes": 16.890716633333334,
  "t0_at": "2026-10-08T20:12:15.074000+00:00",
  "signals": {
    "trigger_signal": {
      "at": "2026-10-08T20:12:15.074000+00:00",
      "days": 0,
      "is_lower_bound": false,
      "measured_at": "2026-10-08T20:12:15.074000+00:00",
      "url": "https://github.com/mongodb/mongo-python-driver/security/advisories/GHSA-98qm-wvgf-w4cf"
    }
  }
}