{"id":"CVE-2026-82398","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 6.15.0, an attacker can craft a PDF that causes long runtimes when the pypdf/_utils.py function read_until_whitespace reads a stream containing a long run of bytes without…","severity":"medium","cwe":["CWE-407","CWE-1046"],"vendor":"pypdf","product":"pypdf","affected":["pypdf < 6.15.0"],"patched":["pypdf 6.15.0"],"published":"2026-08-31","updated":"2026-09-09","sourceUpdated":"2026-09-09T16:49:20.627","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-82398","references":[{"url":"https://github.com/py-pdf/pypdf/commit/4959848e057e37c218dccad7465259210923faaa","label":"security-advisories@github.com"},{"url":"https://github.com/py-pdf/pypdf/pull/3947","label":"security-advisories@github.com"},{"url":"https://github.com/py-pdf/pypdf/releases/tag/6.15.0","label":"security-advisories@github.com"},{"url":"https://github.com/py-pdf/pypdf/security/advisories/GHSA-fc8x-2rww-xw9m","label":"security-advisories@github.com"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-82398"},{"url":"https://github.com/advisories/GHSA-fc8x-2rww-xw9m"},{"url":"https://github.com/py-pdf/pypdf"},{"url":"https://pypi.org/project/pypdf"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-82398.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-82398"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2526567"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-82398"}],"tags":["nvd","ghsa","pip","osv","csaf","vex","red-hat"],"epss":0.00524,"epssPercentile":0.41909,"aliases":["GHSA-fc8x-2rww-xw9m","PYSEC-2026-3912"],"ecosystem":"pip","ingestedAt":"2026-09-02T14:45:30.013Z","cvss":5.3,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","cvssSource":"vendor","slug":"CVE-2026-82398","body":"## Overview\n\npypdf is a free and open-source pure-python PDF library. Prior to 6.15.0, an attacker can craft a PDF that causes long runtimes when the pypdf/_utils.py function read_until_whitespace reads a stream containing a long run of bytes without whitespace. The function repeatedly performs immutable bytes concatenation in a one-byte loop, causing quadratic processing cost for the long non-whitespace input. This issue is fixed in version 6.15.0.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Package advisory (CVE-2026-82398)\n\nAffected packages:\n\n- `pypdf < 6.15.0`\n\nPatched in:\n\n- `pypdf 6.15.0`\n\nSource: https://github.com/advisories/GHSA-fc8x-2rww-xw9m\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Ansible Automation Orchestrator 2026, Exploit Intelligence, Lightspeed Core, OpenShift Lightspeed, Red Hat Ansible Automation Platform 2, Red Hat Enterprise Linux AI (RHEL AI) 3, … · no fix planned: Exploit Intelligence, Red Hat Ansible Automation Platform 2, Red Hat Quay 3, Ansible Automation Orchestrator 2026, … · updated 2026-09-25 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-82398.json)","depth":"sunlit","depthScore":29,"depthScoreParts":{"impact":29.2,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":210665,"id":"CVE-2026-82398","ts":1790322151461,"field":"cvss","old":null,"new":"5.3"}]}