EUVD-2026-38354
GHSA-52x6-gq3r-vpf4
Severity by source
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/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
Network-deliverable crafted PDF requires no privileges; user/service interaction (UI:R) needed to process the file; pure availability impact from infinite loop.
Primary rating from Vendor (https://github.com/py-pdf/pypdf).
CVSS VectorVendor: https://github.com/py-pdf/pypdf
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/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
Lifecycle Timeline
3Blast Radius
ecosystem impact- 1 pypi packages depend on pypdf (1 direct, 0 indirect)
Ecosystem-wide dependent count for version 6.13.0.
DescriptionCVE.org
Impact
An attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires extracting the text in layout mode.
Patches
This has been fixed in pypdf==6.13.0.
Workarounds
If you cannot upgrade yet, consider applying the changes from PR #3830.
AnalysisAI
Infinite loop denial-of-service in pypdf allows an attacker to hang any Python application that processes a crafted PDF using layout-mode text extraction. The vulnerability arises because the /Parent hierarchy traversal in _layout_mode_fonts() lacked cycle detection, so a circular reference structure in a malicious PDF causes the parser to loop indefinitely. …
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Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | Exploitation requires two conditions: (1) the target application must be using pypdf < 6.13.0 and must invoke text extraction with layout mode enabled (specifically the code path through `_layout_mode_fonts()` - triggered by `extraction_mode='layout'` or equivalent); (2) the attacker must be able to supply a PDF file that the application will process, either directly (file upload endpoint) or indirectly (e.g., emailing a document to an ingestion pipeline). … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | Real-world risk is moderate for services that accept untrusted PDF uploads and process them with layout-mode text extraction. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | An attacker submits a crafted PDF to a document-processing web service that uses pypdf with layout-mode text extraction (e.g., a resume parser or invoice OCR endpoint). The PDF contains a circular `/Parent` chain in its page object tree. … |
| Remediation | The primary fix is to upgrade pypdf to version 6.13.0 or later via `pip install --upgrade 'pypdf>=6.13.0'`. … Detailed patch versions, workarounds, and compensating controls in full report. |
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Same technique Denial Of Service
View allVendor StatusVendor
SUSE
Severity: ModerateShare
External POC / Exploit Code
Leaving vuln.today