CVE-2026-84310: pypdf: Possible long runtimes/large memory usage when retrieving outlines

September 1, 2026

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.

References

github.com/advisories/GHSA-23w6-3w8w-8484
github.com/py-pdf/pypdf/commit/d91ab705fd81ed1a9cec175c6958600dea1a4942
github.com/py-pdf/pypdf/pull/3966
github.com/py-pdf/pypdf/releases/tag/6.16.1
github.com/py-pdf/pypdf/security/advisories/GHSA-23w6-3w8w-8484
nvd.nist.gov/vuln/detail/CVE-2026-84310

Code Behaviors & Features

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