Investigate in your agent.

Turn this advisory into a focused investigation. Ask your agent to check your project’s versions, explain the evidence, and suggest a compatible fix.

Your agent needs remote MCP support and access to https://cve.new/mcp.

Read the setup guide

Skip to content
cve.new Create a CVE report
Check your stack
CVE-2026-113793medium6.0

pypdf: Possible infinite loop when removing tree items

Impact

pypdf versions prior to 6.20.1 may enter an infinite loop when removing objects from crafted cyclic PDF trees, blocking the process. The issue is caused by a loop with an unreachable exit condition. It is fixed in version 6.20.1.

Summarized by @cf/meta/llama-3.3-70b-instruct-fp8-fast. Verify details against the original sources.

Affected packages

This source has no supported package-version data for matching. You can read the advisory here, but this record alone cannot power a dependency check.

Affected products

Vendor version evidence. Product records are separate from automatic dependency matching.

py-pdf · GitHub_M

pypdf

1 range
GitHub_M version evidence

Compare with this publisher’s ranges. This does not inspect your installation.

affected

< 6.20.1

unaffected

unknown

Other versions: unknown

Original source description

pypdf is a free and open-source pure-python PDF library. Prior to 6.20.1, removing an object from a crafted cyclic PDF tree, such as an outline item, can enter an infinite loop and block the current process. This issue is fixed in version 6.20.1.

Inside the record

Evidence available

Package identity · not supplied
Version evidence
Remediation guidance · not supplied
Weakness classification
Additional publishers

Describes the evidence in this view, not whether the product is safe.

Original records

CVE-2026-113793

View the latest unmodified CVE JSON from the official source. It may be newer than this imported page.

cve.new JSON →

Underlying weaknesses

The source’s classification of what caused the vulnerability.

CWE-835 ↗

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

GitHub_M

Related →
Contributing organizations · 2
GitHub_M

Assigning organization

2026-10-21
CISA-ADP

Additional data publisher

2026-10-28

What changed

Follow changes
No substantive changes have been recorded here yet. History starts when cve.new observes a change after tracking is enabled; earlier edits are not reconstructed.

Large field values are marked as truncated previews. Original source snapshots remain retained.

References

4 sources
github.com/py-pdf/pypdf/security/advisories/GHSA-9mx8-4j7g-633p
Security advisoryGitHub_M
github.com/py-pdf/pypdf/pull/4188
PatchGitHub_M
github.com/py-pdf/pypdf/commit/c9c35b4471c2eb5fe078094f6c816e69d4ed25a0
PatchGitHub_M
github.com/py-pdf/pypdf/releases/tag/6.20.1
Release notesGitHub_M