Description
pypdf is a free and open-source pure-python PDF library. Prior to 6.21.3, pypdf can consume excessive memory while opening a crafted PDF containing cross-reference streams that declare very large entry counts. Highly compressible streams and /Prev chains can multiply the number of parsed entries across a document, while negative /Index counts can bypass the existing per-stream clamp. This issue is fixed in version 6.21.3.
Published: 2026-10-29
Score: 7.1 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories

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History

Fri, 30 Oct 2026 17:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Fri, 30 Oct 2026 12:30:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H'}

threat_severity

Moderate


Thu, 29 Oct 2026 21:45:00 +0000

Type Values Removed Values Added
First Time appeared Py-pdf
Py-pdf pypdf
Vendors & Products Py-pdf
Py-pdf pypdf

Thu, 29 Oct 2026 20:45:00 +0000

Type Values Removed Values Added
Description pypdf is a free and open-source pure-python PDF library. Prior to 6.21.3, pypdf can consume excessive memory while opening a crafted PDF containing cross-reference streams that declare very large entry counts. Highly compressible streams and /Prev chains can multiply the number of parsed entries across a document, while negative /Index counts can bypass the existing per-stream clamp. This issue is fixed in version 6.21.3.
Title pypdf: Possible large memory usage when parsing cross-reference streams
Weaknesses CWE-400
CWE-770
References
Metrics cvssV4_0

{'score': 7.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-10-30T16:00:30.516Z

Reserved: 2026-10-29T16:04:48.729Z

Link: CVE-2026-119209

cve-icon Vulnrichment

Updated: 2026-10-30T15:47:30.932Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-10-29T21:17:20.230

Modified: 2026-10-30T17:07:53.700

Link: CVE-2026-119209

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-10-29T20:43:03Z

Links: CVE-2026-119209 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-10-29T21:30:15Z

Weaknesses