Infinite Loop when a comment isn't followed by a character in pypdf

{
  "id": "1ab927dc43bcc9db06a5f9be3583ca93ad1967f3ebd545b184f011d13ee13055",
  "url": "https://osv.dev/vulnerability/CVE-2023-36464",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Infinite Loop when a comment isn't followed by a character in pypdf",
    "summary": "pypdf is an open source, pure-python PDF library. In affected versions an attacker may craft a PDF which leads to an infinite loop if `__parse_content_stream` is executed. That is, for example, the case if the user extracted text from such a PDF. This issue was introduced in pull request #969 and resolved in pull request #1828. Users are advised to upgrade. Users unable to upgrade may modify the line `while peek not in (b\"\\r\", b\"\\n\")` in `pypdf/generic/_data_structures.py` to `while peek not in (b\"\\r\", b\"\\n\", b\"\")`.",
    "evidence": "osv:CVE-2023-36464",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2023-36464",
      "aliases": [
        "CVE-2023-36464",
        "GHSA-4vvm-4w3v-6mr8",
        "PYSEC-2026-1835",
        "PYSEC-2026-3008"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/py-pdf/pypdf",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "0096c99031955b15bd30834e5566076d9528f59d"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:pypdf_project:pypdf:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "3.9.0"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "3.8.1",
            "3.8.0",
            "3.7.1",
            "3.7.0",
            "3.6.0",
            "3.5.2",
            "3.5.1",
            "3.5.0",
            "3.4.1",
            "3.4.0",
            "3.3.0",
            "3.2.1",
            "3.2.0",
            "3.0.0",
            "3.1.0",
            "2.12.1",
            "2.12.0",
            "2.11.2",
            "2.11.1",
            "2.11.0",
            "2.10.9",
            "2.10.8",
            "2.10.7",
            "2.10.6",
            "2.10.5",
            "2.10.4",
            "2.10.3",
            "2.10.2",
            "2.10.1",
            "2.10.0",
            "2.9.0",
            "2.8.1",
            "2.8.0",
            "2.7.0",
            "2.6.0",
            "2.5.0",
            "2.4.2",
            "2.4.1",
            "2.4.0",
            "2.3.1",
            "2.3.0",
            "2.2.1",
            "2.2.0",
            "2.1.1",
            "2.1.0",
            "2.0.0",
            "1.28.2",
            "1.28.1",
            "1.28.0",
            "1.27.12",
            "1.27.11",
            "1.27.10",
            "1.27.9",
            "1.27.8",
            "1.27.7",
            "1.27.6",
            "1.27.5",
            "1.27.4",
            "1.27.3",
            "1.27.2",
            "1.27.1",
            "1.27.0",
            "v1.24",
            "1.26.0",
            "v1.25.1",
            "v1.25",
            "v1.23",
            "v1.22",
            "v1.21",
            "v1.20",
            "v1.19",
            "v1.18",
            "v1.17"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-36464.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:24.995829930Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/36xxx/CVE-2023-36464.json",
        "https://github.com/py-pdf/pypdf/security/advisories/GHSA-4vvm-4w3v-6mr8",
        "https://nvd.nist.gov/vuln/detail/CVE-2023-36464",
        "https://github.com/py-pdf/pypdf/pull/1828",
        "https://github.com/py-pdf/pypdf/pull/969"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-835"
        ],
        "cna_assigner": "GitHub_M",
        "unresolved_ranges": [
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": " pypdf: < 3.90"
                  },
                  {
                    "last_affected": " pypdf: < 3.90"
                  },
                  {
                    "introduced": "PyPDF2: >= 2.2.0"
                  },
                  {
                    "last_affected": "PyPDF2: >= 2.2.0"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StandaloneSingleVersion"
              }
            ]
          }
        ],
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/36xxx/CVE-2023-36464.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2023-36464",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 491653,
  "published_at": "2023-06-27T21:24:30.685+00:00"
}