CVE-2026-119204— pypdf: Possible large memory usage when parsing page tree

Quick assessment

Affected

py-pdf pypdf

Exploitation

No confirmed in-the-wild exploitation; assess based on exposure

Recommended action

Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

pypdf 是一个免费且开源的纯 Python PDF 库。在 6.21.4 版本之前，pypdf 在解析包含大量共享资源的精心构造的 PDF 页面树时，可能会消耗过量内存。页面树扁平化过程会复制页面字典及继承的资源条目，且未设置文档级别的条目预算，导致精心构造的资源结构引发不成比例的内存分配。该问题已在 6.21.4 版本中修复。

CVSS 7.1 · High Updated Oct 30, 2026

Possible ATT&CK Techniques 1 AI

T1068.015

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Vulnerability Information

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Vulnerability Title

pypdf: Possible large memory usage when parsing page tree

Source: CVE Program / CVE List V5

Vulnerability Description

pypdf is a free and open-source pure-python PDF library. Prior to 6.21.4, pypdf can consume excessive memory while parsing a crafted PDF page tree containing many shared resources. Page-tree flattening copies page dictionary and inherited resource entries without a document-wide entry budget, allowing the crafted resource structure to cause disproportionate allocations. This issue is fixed in version 6.21.4.

Source: CVE Program / CVE List V5

CVSS Information

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

Source: CVE Program / CVE List V5

Vulnerability Type

未加控制的资源消耗(资源穷尽)

Source: CVE Program / CVE List V5

Affected Products

Vendor	Product	Affected Versions	CPE	Subscribe
py-pdf	pypdf	< 6.21.4	-

II. Public POCs for CVE-2026-119204

#	POC Description	Source Link	Shenlong Link

AI-Generated POC Premium

No public POC found.

III. Intelligence Information for CVE-2026-119204

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Other References for CVE-2026-119204 (4)

https://github.com/py-pdf/pypdf/pull/4290 x_refsource_MISC
https://github.com/py-pdf/pypdf/releases/tag/6.21.4 x_refsource_MISC
https://github.com/py-pdf/pypdf/security/advisories/GHSA-cggf-277g-3q54 x_refsource_CONFIRM
https://github.com/py-pdf/pypdf/commit/ea4ac663133f1b3de1d7a8f2e6fa239802fde79e x_refsource_MISC

https://www.cve.org/CVERecord?id=CVE-2026-119204

Same Patch Batch · py-pdf · 2026-10-29 · 7 CVEs total

CVE-2026-119206	7.1 HIGH	pypdf: Possible long runtimes when retrieving page labels
CVE-2026-119203	7.1 HIGH	pypdf: Possible infinite loop when hitting EOF in standard xref table during trailer searc
CVE-2026-119207	7.1 HIGH	pypdf: Possible large memory usage for exceptions in strict mode
CVE-2026-119205	7.1 HIGH	pypdf: Possible infinite loop when cloning dictionaries
CVE-2026-119209	7.1 HIGH	pypdf: Possible large memory usage when parsing cross-reference streams
CVE-2026-119208	7.1 HIGH	pypdf: Possible long runtimes/large memory usage for encrypted PDF files

IV. Related Vulnerabilities

Same product: pypdf

Same vendor: py-pdf

Same weakness: CWE-400