Vulnerability GHSA-9mx8-4j7g-633p
Medium Risk
MEDIUM RISK
CVSS Score: 6.0
Score Range: 4.0–6.9
Medium severity vulnerabilities (CVSS 4.0–6.9). Important issues that meaningfully reduce security confidence.
1 hour ago
October 21, 2026 at 04:55 PM UTC
pypdf: Possible infinite loop when removing tree items
1.0 - 6.20.0
1.0 - 6.20.0
Summary
pypdf: Possible infinite loop when removing tree items
Details
Impact
An attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires removing an object from a tree, for example an outline item.
Patches
This has been fixed in pypdf==6.20.1.
Workarounds
If you cannot upgrade yet, consider applying the changes from PR #4188.
Related Vulnerabilities
Other vulnerabilities affecting the same packages
Medium Risk
1 hour ago
pypdf: Possible infinite loop in PdfWriter.find_outline_item
1.0 - 6.20.0 GHSA-qfv9-64jg-mh7p
1.0 - 6.20.0 GHSA-qfv9-64jg-mh7p
Medium Risk
1 hour ago
pypdf: Possible infinite loop when hitting EOF in standard xref table
1.0 - 6.19.0 GHSA-39mj-jf6j-2qj3
1.0 - 6.19.0 GHSA-39mj-jf6j-2qj3
Medium Risk
1 hour ago
pypdf: Possible large memory usage for streams with multiple filters
1.0 - 6.19.0 GHSA-7mh2-4gg2-979f
1.0 - 6.19.0 GHSA-7mh2-4gg2-979f
Unknown
20 days ago
pypdf: Possible long runtimes for partially malformed FlateDecode streams (Follow-up)
1.0 - 6.18.0 PYSEC-2026-4156
1.0 - 6.18.0 PYSEC-2026-4156
Unknown
20 days ago
pypdf: Possible long runtimes when generating appearance streams
1.0 - 6.18.1 PYSEC-2026-4157
1.0 - 6.18.1 PYSEC-2026-4157
Impacted packages
Timeline
Published
1 hour ago
October 21, 2026 at 04:55 PM UTC
Fixed (6.20.1)
9 days ago
October 12, 2026 at 04:14 PM UTC
Last Modified
1 hour ago
October 21, 2026 at 05:00 PM UTC