{"id":"CVE-2023-46250","aliases":["GHSA-wjcc-cq79-p63f","PYSEC-2026-1834"],"title":"Possible Infinite Loop when PdfWriter(clone_from) is used with a PDF","summary":"Possible Infinite Loop when PdfWriter(clone_from) is used with a PDF","severity":"medium","cvss":5.1,"cvssVector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","vendor":"pypdf","product":"pypdf","ecosystem":"pip","affected":["pypdf >= 3.7.0, < 3.17.0"],"patched":["pypdf 3.17.0"],"published":"2023-10-31","updated":"2026-09-10","sourceUpdated":"2026-09-10T03:50:08.746181393Z","source":"OSV","sourceUrl":"https://osv.dev/vulnerability/GHSA-wjcc-cq79-p63f","references":[{"url":"https://github.com/py-pdf/pypdf/security/advisories/GHSA-wjcc-cq79-p63f"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2023-46250"},{"url":"https://github.com/py-pdf/pypdf/pull/2264"},{"url":"https://github.com/py-pdf/pypdf/commit/9b23ac3c9619492570011d551d521690de9a3e2d"},{"url":"https://github.com/py-pdf/pypdf"}],"tags":["osv","pip"],"epss":0.00243,"epssPercentile":0.15788,"ingestedAt":"2026-07-08T18:25:53.824Z","slug":"CVE-2023-46250","body":"## Overview\n\n### Impact\nAn attacker who uses this vulnerability can craft a PDF which leads to an infinite loop.\nThis infinite loop blocks the current process and can utilize a single core of the CPU by 100%. It does not affect memory usage.\n\nThat is, for example, the case when the pypdf-user manipulates an incoming malicious PDF e.g. by merging it with another PDF or by adding annotations.\n\n### Patches\nThe issue was fixed with #2264\n\n### Workarounds\nIf you cannot update your version of pypdf, you should modify `pypdf/generic/_data_structures.py` just like #2264 did.\n\n## Affected packages\n\n- `pypdf >= 3.7.0, < 3.17.0`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `pypdf 3.17.0`","depth":"sunlit","depthScore":28,"depthScoreParts":{"impact":28.1,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}