Non-painting replaced elements amplify to thousands of blank PDF pages (denial of service)

{
  "id": "967bf9d60a2961a1ce5a715dbf18ea39d0054391fe4fcbe4f4a65f2a4e7d94c9",
  "url": "https://osv.dev/vulnerability/RUSTSEC-2026-0201",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Non-painting replaced elements amplify to thousands of blank PDF pages (denial of service)",
    "summary": "`fulgur` converts untrusted HTML/CSS into PDF, commonly on a server that processes input supplied by many tenants. In versions prior to 0.26.0, a childless box that resolves to a pathologically tall height was amplified into thousands of blank PDF pages, even when it produces no visible output. The childless-collapse defense that would normally collapse such a box was gated by a tag-only \"replaced content\" check, so any non-painting replaced element bypassed it, including an unresolved `src` (the common offline-first case), a `visibility:hidden` image, an undecodable image format, and an empty ``. A trailing-sibling variant of the same gap was also open. A few bytes of HTML therefore amplified into roughly `MAX_PAGES` (10,000) blank pages; the renderer allocates and runs a per-page loop over them, producing CPU and memory exhaustion. An attacker able to submit HTML to a fulgur-based conversion service can trigger this with a trivially small payload, denying service to the host and any co-tenants. Fixed in 0.26.0: the tag-only gate was removed so that any pathologically tall childless box collapses regardless of whether it is a replaced element, closing the missing-`src`, `visibility:hidden`, undecodable-format, and empty-`` vectors along with the trailing-sibling variant. Versions prior to 0.19.0 additionally lacked any page-count cap, allowing an unbounded (rather than 10,000-page) variant of this amplification; that earlier variant is tracked separately as GHSA-j5cx-ph8g-95",
    "evidence": "osv:RUSTSEC-2026-0201",
    "products": [
      {
        "name": {
          "value": "fulgur",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "0.26.0",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "RUSTSEC-2026-0201",
      "aliases": [
        "CVE-2026-68537",
        "GHSA-4rf6-qx84-q9fv",
        "RUSTSEC-2026-0201"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "0.0.0-0"
                },
                {
                  "fixed": "0.26.0"
                }
              ]
            }
          ],
          "package": {
            "name": "fulgur",
            "purl": "pkg:cargo/fulgur",
            "ecosystem": "crates.io"
          },
          "database_specific": {
            "cvss": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "source": "https://github.com/rustsec/advisory-db/blob/osv/crates/RUSTSEC-2026-0201.json",
            "categories": [
              "denial-of-service"
            ],
            "informational": null
          },
          "ecosystem_specific": {
            "affects": {
              "os": [],
              "arch": [],
              "functions": []
            },
            "affected_functions": null
          }
        }
      ],
      "modified": "2026-10-12T18:00:14.311210820Z",
      "provider": "osv",
      "references": [
        "https://crates.io/crates/fulgur",
        "https://rustsec.org/advisories/RUSTSEC-2026-0201.html",
        "https://github.com/fulgur-rs/fulgur/pull/575"
      ],
      "provider_metadata": {
        "license": "CC0-1.0"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-68537",
        "evidence": "/aliases"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 306460,
  "published_at": "2026-07-05T12:00:00+00:00"
}