lopdf has a stack overflow via deeply nested PDF objects

{
  "id": "241fa0cfbe1bc72006b115bec89d4e09e9b4dd76f1491d329697fb2725741e27",
  "url": "https://osv.dev/vulnerability/GHSA-6fj4-rcr3-r7rr",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "lopdf has a stack overflow via deeply nested PDF objects",
    "summary": "`lopdf::Document::load_mem` (and the other `load*` entry points) parses nested PDF arrays and dictionaries with unbounded recursion. A small crafted PDF whose Catalog contains a deeply nested array (`/X [[[ … ]]]`, on the order of 10,000 levels) exhausts the call stack and aborts the process with `SIGABRT`. Because this is a stack-overflow abort rather than a `panic!`, it cannot be caught with `catch_unwind`: any service that parses untrusted PDF input with lopdf can be crashed by a ~21 KB file, resulting in a denial of service. Confirmed on lopdf 0.41.0 and earlier; fixed in 0.42.0. Default configuration, no features changed. ## Proof of concept ```rust fn main() { let bytes = std::fs::read(\"poc.pdf\").unwrap(); // ~10,380-deep nested array in the Catalog let _ = lopdf::Document::load_mem(&bytes); // stack overflow -> SIGABRT } ``` An equivalent PoC is a minimal PDF whose Catalog `/X` value is `\"[\" * 10380 + \"]\" * 10380`. ## Suggested fix Enforce a maximum object-nesting depth in the parser and return an `Err` instead of recursing without bound.",
    "evidence": "osv:GHSA-6fj4-rcr3-r7rr",
    "products": [
      {
        "name": {
          "value": "lopdf",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "0.42.0",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "GHSA-6fj4-rcr3-r7rr",
      "aliases": [
        "GHSA-6fj4-rcr3-r7rr",
        "RUSTSEC-2026-0187"
      ],
      "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"
                },
                {
                  "fixed": "0.42.0"
                }
              ]
            }
          ],
          "package": {
            "name": "lopdf",
            "purl": "pkg:cargo/lopdf",
            "ecosystem": "crates.io"
          },
          "database_specific": {
            "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-6fj4-rcr3-r7rr/GHSA-6fj4-rcr3-r7rr.json"
          }
        }
      ],
      "modified": "2026-10-17T15:26:01.305676388Z",
      "provider": "osv",
      "references": [
        "https://github.com/J-F-Liu/lopdf/issues/502",
        "https://github.com/J-F-Liu/lopdf/pull/503",
        "https://github.com/J-F-Liu/lopdf/commit/c755394ad7dd651ccfe77c618f90ab779da1dfd9",
        "https://github.com/J-F-Liu/lopdf",
        "https://rustsec.org/advisories/RUSTSEC-2026-0187.html"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-1124"
        ],
        "severity": "HIGH",
        "github_reviewed": true,
        "nvd_published_at": null,
        "github_reviewed_at": "2026-10-16T19:55:39Z"
      }
    },
    "related_cves": [],
    "security_relevant": true,
    "severity_evidence": "/database_specific/severity"
  },
  "source_id": "core-osv",
  "document_id": 362247,
  "published_at": "2026-10-16T19:55:39+00:00"
}