pypdf has long runtimes for wrong size values in cross-reference and object streams
### Impact An attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires cross-reference streams with wrong large `/Size` values or object streams with wrong large `/N` values. ### Patches This has been fixed in [pypdf==6.10.1](https://github.com/py-pdf/pypdf/releases/tag/6.10.1). ### Workarounds If you cannot upgrade yet, consider applying the changes from PR [#3733](https://github.com/py-pdf/pypdf/pull/3733).
describes (1)
Related CVEs.
| ID | severity | exploitable | ||
|---|---|---|---|---|
| CVE-2026-41168US | medium5.3 | — | ||
pypdf is a free and open-source pure-python PDF library. An attacker who uses a vulnerability present in versions prior to 6.10.1 can craft a PDF which leads to long runtimes. This… | ||||
references
External citations — patches, advisories, analysis.
- https://github.com/advisories/GHSA-jj6c-8h6c-hppxADVISORY
- https://github.com/py-pdf/pypdfPACKAGE
- https://github.com/py-pdf/pypdf/commit/62338e9d36419cf193ccec7331784f45df1d70b3WEB
- https://github.com/py-pdf/pypdf/pull/3733WEB
- https://github.com/py-pdf/pypdf/releases/tag/6.10.1WEB
- https://github.com/py-pdf/pypdf/security/advisories/GHSA-jj6c-8h6c-hppxWEB
- https://nvd.nist.gov/vuln/detail/CVE-2026-41168ADVISORY
- https://pypi.org/project/pypdfPACKAGE
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