CVE-2026-33699— pypdf: Possible infinite loop during recovery attempts in DictionaryObject.read_from_stream
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py-pdf开源的一个免费开源的纯 python PDF 库。能够拆分、合并、裁剪和转换 PDF 文件的页面。 pypdf 6.9.2之前版本存在安全漏洞，该漏洞源于攻击者可制作导致无限循环的PDF文件。
Possible ATT&CK Techniques 1 AI
T1190 · Exploit Public-Facing Application
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I. Basic Information for CVE-2026-33699
Vulnerability Information
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Vulnerability Title
pypdf: Possible infinite loop during recovery attempts in DictionaryObject.read_from_stream
Source: CVE Program / CVE List V5
Vulnerability Description
pypdf is a free and open-source pure-python PDF library. Versions prior to 6.9.2 have a vulnerability in which an attacker can craft a PDF which leads to an infinite loop. This requires reading a file in non-strict mode. This has been fixed in pypdf 6.9.2. If users cannot upgrade yet, consider applying the changes from the patch manually.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U
Source: CVE Program / CVE List V5
Vulnerability Type
不可达退出条件的循环(无限循环)
Source: CVE Program / CVE List V5
Vulnerability Title
pypdf 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
pypdf是py-pdf开源的一个免费开源的纯 python PDF 库。能够拆分、合并、裁剪和转换 PDF 文件的页面。 pypdf 6.9.2之前版本存在安全漏洞，该漏洞源于攻击者可制作导致无限循环的PDF文件。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)
Affected Products
II. Public POCs for CVE-2026-33699
| # | POC Description | Source Link | Shenlong Link |
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Patches & Fixes for CVE-2026-33699 (1)
Vendor Advisories for CVE-2026-33699 (1)
Vendor Pages for CVE-2026-33699 (1)
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Release Version 6.9.2, 2026-03-23 · py-pdf/pypdf · GitHub x_refsource_MISC
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Same weakness: CWE-835
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V. Comments for CVE-2026-33699
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