{
  "site": "https://pwn.watch",
  "generatedAt": "2026-10-22T21:29:54.052Z",
  "tag": {
    "id": "polyfill",
    "label": "Polyfill",
    "isStack": false,
    "url": "https://pwn.watch/t/polyfill",
    "feed": "https://pwn.watch/t/polyfill/feed.xml"
  },
  "counts": {
    "incidents": 1,
    "live": 0,
    "notFullyPatched": 0,
    "patched": 1
  },
  "incidents": [
    {
      "slug": "polyfill-io-supply-chain-attack",
      "title": "polyfill.io CDN turned malicious on 100k+ sites",
      "url": "https://pwn.watch/i/polyfill-io-supply-chain-attack",
      "json": "https://pwn.watch/i/polyfill-io-supply-chain-attack.json",
      "status": "closed",
      "severity": "high",
      "patchStatus": "patched",
      "product": "polyfill.io CDN",
      "tags": [
        "polyfill",
        "javascript",
        "cdn",
        "supply-chain",
        "cloudflare"
      ],
      "cveIds": [],
      "affectedVersions": [
        "Any site loading scripts from cdn.polyfill.io"
      ],
      "fixedVersions": [
        "Remove polyfill.io references or switch to the Cloudflare/Fastly mirrors"
      ],
      "startedAt": "2024-06-25",
      "closedAt": "2024-06-27",
      "updatedAt": "2024-06-27",
      "summary": "The polyfill.io domain and GitHub account were bought in February 2024 by a Chinese company. The CDN, embedded via cdn.polyfill.io on more than 100,000 sites, then served malicious JavaScript that redirected some mobile visitors to a sports betting site. Sansec exposed it on 2024-06-25. Cloudflare began rewriting polyfill.io links to its own mirror, and Namecheap put the domain on hold.",
      "xPost": null
    }
  ],
  "posts": [],
  "changes": [
    {
      "incident": "polyfill-io-supply-chain-attack",
      "incidentTitle": "polyfill.io CDN turned malicious on 100k+ sites",
      "severity": "high",
      "status": "closed",
      "patchStatus": "patched",
      "date": "2024-06-27",
      "title": "Cloudflare rewrites cdn.polyfill.io to its mirror; Namecheap puts the domain on hold",
      "body": null,
      "sourceUrl": "https://sansec.io/research/polyfill-supply-chain-attack",
      "url": "https://pwn.watch/i/polyfill-io-supply-chain-attack"
    },
    {
      "incident": "polyfill-io-supply-chain-attack",
      "incidentTitle": "polyfill.io CDN turned malicious on 100k+ sites",
      "severity": "high",
      "status": "closed",
      "patchStatus": "patched",
      "date": "2024-06-25",
      "title": "Sansec reports the polyfill.io supply-chain attack hitting 100k+ sites",
      "body": null,
      "sourceUrl": "https://sansec.io/research/polyfill-supply-chain-attack",
      "url": "https://pwn.watch/i/polyfill-io-supply-chain-attack"
    }
  ]
}