pypdf: Possible infinite loop when processing outlines/bookmarks in writer

When

2026-06-16 14:05 UTC

Where

Global (internet)

Category

cyber_advisory · pip

### Impact An attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires merging a file with outlines into a writer. ### Patches This has been fixed in [pypdf==6.13.0](https://github.com/py-pdf/pypdf/releases/tag/6.13.0). ### Workarounds If you cannot upgrade yet, consider applying the changes from PR [#3830](https://github.com/py-pdf/pypdf/pull/3830).

Sources

• GitHub Advisory Database ↗ · first seen 2026-06-16 14:05 UTC

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Correlated events

Computed by the Defaxon correlation engine — linked by shared actors, co-location, and temporal proximity. Scored hypotheses, never causal claims.

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