pypdf: Possible long runtimes/large memory usage when retrieving outlines
### Impact An attacker who uses this vulnerability can craft a PDF which leads to long runtimes and large memory consumption. This requires accessing the outlines of a document with either lots of entries or nested outlines with long re-used nesting paths. ### Patches This has been fixed in [pypdf==6.16.1](https://github.com/py-pdf/pypdf/releases/tag/6.16.1). ### Workarounds If you cannot upgrade yet, consider applying the changes from PR [#3966](https://github.com/py-pdf/pypdf/pull/3966).
describes (1)
Related CVEs.
| ID | severity | exploitable | ||
|---|---|---|---|---|
| CVE-2026-84310US | low3.3 | — | ||
pypdf is a free and open-source pure-python PDF library. Prior to 6.16.1, an attacker can craft a PDF that causes pypdf/_doc_common.py _get_outline to consume long runtimes and lar… | ||||
references
External citations — patches, advisories, analysis.
- https://github.com/advisories/GHSA-23w6-3w8w-8484ADVISORY
- https://github.com/py-pdf/pypdfPACKAGE
- https://github.com/py-pdf/pypdf/commit/d91ab705fd81ed1a9cec175c6958600dea1a4942WEB
- https://github.com/py-pdf/pypdf/pull/3966WEB
- https://github.com/py-pdf/pypdf/releases/tag/6.16.1WEB
- https://github.com/py-pdf/pypdf/security/advisories/GHSA-23w6-3w8w-8484WEB
- https://nvd.nist.gov/vuln/detail/CVE-2026-84310ADVISORY
- https://pypi.org/project/pypdfPACKAGE
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