{
  "affected": [
    {
      "database_specific": {
        "unresolved_ranges": [
          {
            "events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "4.4.9"
              }
            ]
          },
          {
            "events": [
              {
                "introduced": "0"
              },
              {
                "last_affected": "9.0"
              }
            ]
          }
        ]
      },
      "ranges": [
        {
          "database_specific": {
            "versions": [
              {
                "introduced": "0"
              },
              {
                "fixed": "1.36.2"
              }
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "8b5733a58d3acf9fb62815e14699c986bd1c2fdc"
            }
          ],
          "repo": "https://github.com/gorhill/ublock",
          "type": "GIT"
        },
        {
          "database_specific": {
            "versions": [
              {
                "introduced": "0"
              },
              {
                "fixed": "1.4.2"
              }
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "be3990e24e39f46a22dadb247028bae75621d75d"
            }
          ],
          "repo": "https://github.com/gorhill/umatrix",
          "type": "GIT"
        }
      ]
    }
  ],
  "details": "uBlock Origin before 1.36.2 and nMatrix before 4.4.9 support an arbitrary depth of parameter nesting for strict blocking, which allows crafted web sites to cause a denial of service (unbounded recursion that can trigger memory consumption and a loss of all blocking functionality).",
  "id": "CVE-2021-36773",
  "modified": "2026-03-13T21:47:16.772046915Z",
  "published": "2021-07-18T04:15:08.110Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://lists.debian.org/debian-lts-announce/2022/06/msg00024.html"
    },
    {
      "type": "REPORT",
      "url": "https://news.ycombinator.com/item?id=27833752"
    },
    {
      "type": "EVIDENCE",
      "url": "https://github.com/vtriolet/writings/blob/main/posts/2021/ublock_origin_and_umatrix_denial_of_service.adoc"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}