CVE-2026-113792

pypdf: Possible infinite loop in PdfWriter.find_outline_item

pypdf is a free and open-source pure-python PDF library. Prior to 6.20.1, calling PdfWriter.find_outline_item on a crafted PDF with a cyclic outline hierarchy can enter an infinite loop and block the current process. This issue is fixed in version 6.20.1.

Affected

py-pdf · pypdf

CVSS v4.0 GITHUB

6.0 MEDIUMCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/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

CVSS v4.0 GitHub

6.0 MEDIUMCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

EPSS

0.47% chance of exploitation in the next 30 days, 40th percentile

Published

2026-10-21

Updated

2026-10-23

Proof-of-concept exploits (1)

• https://raw.githubusercontent.com/8hw3/pillow-uaf-research/a4477ec0cfb05e4fda8a567e559170…ARCHIVED
  3 files

  encode.cencode.cpoc/04_pypdf_dos.py

CVE references

• advisories/GHSA-qfv9-64jg-mh7pADVISORY
• py-pdf/pypdf/commit/c9c35b4471c2eb5fe078094f6c816e69d4ed25a0REFERENCE
• py-pdf/pypdf/pull/4188REFERENCE
• py-pdf/pypdf/releases/tag/6.20.1REFERENCE
• py-pdf/pypdf/security/advisories/GHSA-qfv9-64jg-mh7pREFERENCE

References

• CVE Record
• NVD entry