{"id":"CVE-2026-102997","title":"pypdf is a free and open-source pure-python PDF library","summary":"pypdf is a free and open-source pure-python PDF library. Prior to 6.18.1, a crafted PDF containing a partially malformed /FlateDecode stream with padded data can force pypdf/filters.py to use inefficient byte-by-byte decompression while …","severity":"high","cvss":8.7,"cvssVector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","cwe":["CWE-400","CWE-407"],"vendor":"py-pdf","product":"pypdf","affected":["pypdf < 6.18.1"],"published":"2026-09-30","updated":"2026-09-30","sourceUpdated":"2026-09-30T21:17:07.020","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-102997","references":[{"url":"https://github.com/py-pdf/pypdf/commit/d9d38cf99b115deb562d3b68f36c33027bc04f79","label":"security-advisories@github.com"},{"url":"https://github.com/py-pdf/pypdf/pull/4073","label":"security-advisories@github.com"},{"url":"https://github.com/py-pdf/pypdf/releases/tag/6.18.1","label":"security-advisories@github.com"},{"url":"https://github.com/py-pdf/pypdf/security/advisories/GHSA-jw7q-gvrg-4vj3","label":"security-advisories@github.com"}],"tags":["nvd","cve.org"],"cvssSource":"cna","ingestedAt":"2026-09-30T21:25:07.839Z","slug":"CVE-2026-102997","body":"## Overview\n\npypdf is a free and open-source pure-python PDF library. Prior to 6.18.1, a crafted PDF containing a partially malformed /FlateDecode stream with padded data can force pypdf/filters.py to use inefficient byte-by-byte decompression while the earlier recovery counter fails to advance for bytes that successfully decode, causing long runtimes and application unavailability. This is a residual issue after the malformed FlateDecode recovery fix. This issue is fixed in version 6.18.1.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":48,"depthScoreParts":{"impact":47.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}