CVE-2026-71852: pypdf: Possible long runtimes/large memory usage for large CID font width ranges

August 7, 2026

An attacker who uses this vulnerability can craft a PDF which leads to long runtimes and large memory consumption. This requires parsing the font width entries of a font with unusually large values, for example during text extraction.

References

github.com/advisories/GHSA-fwg2-594c-jp42
github.com/py-pdf/pypdf/commit/51cb6acf9e8a35b77e90b4d87d28fe3e1416d7d7
github.com/py-pdf/pypdf/pull/3946
github.com/py-pdf/pypdf/releases/tag/6.15.0
github.com/py-pdf/pypdf/security/advisories/GHSA-fwg2-594c-jp42
nvd.nist.gov/vuln/detail/CVE-2026-71852

Code Behaviors & Features

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