{"id":"CVE-2023-36464","aliases":["GHSA-4vvm-4w3v-6mr8","PYSEC-2026-1835","PYSEC-2026-3008"],"url":"https://o3.security/vulnerability/CVE-2023-36464","summary":"Infinite Loop when a comment isn't followed by a character in pypdf","details":"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\"\")`.","published":"2023-06-27T21:24:30.685Z","modified":"2026-07-15T01:49:15.702785445Z","cvss":{"score":6.2,"severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":1,"affectedPackages":[{"ecosystem":"PyPI","name":"pypdf","fixedVersion":"3.9.0"},{"ecosystem":"PyPI","name":"pypdf2","fixedVersion":null}],"fix":{"url":"https://github.com/py-pdf/pypdf/pull/1828","label":"py-pdf/pypdf#1828"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/36xxx/CVE-2023-36464.json"},{"type":"ADVISORY","url":"https://github.com/py-pdf/pypdf/security/advisories/GHSA-4vvm-4w3v-6mr8"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-36464"},{"type":"FIX","url":"https://github.com/py-pdf/pypdf/pull/1828"},{"type":"FIX","url":"https://github.com/py-pdf/pypdf/pull/969"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-15T01:49:15.702785445Z"}}