pypdf: Possible infinite loop during recovery attempts in DictionaryObject.read_from_stream

MITRE NVD CVE.ORG JSON API Print: PDF PDF

Summary

CVECVE-2026-33699
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-03-27 01:16:19 UTC
Updated2026-04-01 16:01:35 UTC
Descriptionpypdf 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.

Risk And Classification

Primary CVSS: v4.0 4.6 MEDIUM from [email protected]

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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS: 0.000490000 probability, percentile 0.152030000 (date 2026-04-05)

Problem Types: CWE-835 | CWE-835 CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop')

VersionSourceTypeScoreSeverityVector
4.0[email protected]Secondary4.6MEDIUMCVSS: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/C...
4.0CNADECLARED4.6MEDIUMCVSS: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
3.1[email protected]Primary7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS v4.0 Breakdown

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
Present
Privileges Required
None
User Interaction
None
Confidentiality
None
Integrity
None
Availability
High
Sub Conf.
None
Sub Integrity
None
Sub Availability
None

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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Application Pypdf Project Pypdf All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Py-pdf Pypdf affected < 6.9.2 Not specified

References

ReferenceSourceLinkTags
github.com/py-pdf/pypdf/pull/3693 [email protected] github.com Issue Tracking, Patch
github.com/py-pdf/pypdf/security/advisories/GHSA-87mj-5ggw-8qc3 [email protected] github.com Patch, Vendor Advisory
github.com/py-pdf/pypdf/releases/tag/6.9.2 [email protected] github.com Product, Release Notes
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis
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