{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:13",
        "name": "quickjs"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "quickjs"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "A vulnerability exists in the QuickJS engine's BigInt string parsing logic (js_bigint_from_string) when attempting to create a BigInt from a string with an excessively large number of digits.  The function calculates the necessary number of bits (n_bits) required to store the BigInt using the formula:  $$\\text{n\\_bits} = (\\text{n\\_digits} \\times 27 + 7) / 8 \\quad (\\text{for radix 10})$$    *  For large input strings (e.g., $79,536,432$ digits or more for base 10), the intermediate calculation $(\\text{n\\_digits} \\times 27 + 7)$ exceeds the maximum value of a standard signed 32-bit integer, resulting in an Integer Overflow.     *  The resulting n_bits value becomes unexpectedly small or even negative due to this wrap-around.     *  This flawed n_bits is then used to compute n_limbs, the number of memory \"limbs\" needed for the BigInt object. Since n_bits is too small, the calculated n_limbs is also significantly underestimated.     *  The function proceeds to allocate a JSBigInt object using this underestimated n_limbs.     *  When the function later attempts to write the actual BigInt data into the allocated object, the small buffer size is quickly exceeded, leading to a Heap Out-of-Bounds Write as data is written past the end of the allocated r-\u003etab array.",
  "id": "DEBIAN-CVE-2025-62496",
  "modified": "2026-09-01T19:47:46.437389189Z",
  "published": "2025-10-16T16:15:40.260Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2025-62496"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "upstream": [
    "CVE-2025-62496"
  ]
}