CVE-2026-48156: pypdf: Possible long runtimes for zero-only width values in cross-reference streamsuntimes for zero-only width values in cross-reference streams

June 12, 2026

An attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires cross-reference streams with /W [0 0 0] values and large /Size values.

References

github.com/advisories/GHSA-248m-82v9-q6g6
github.com/py-pdf/pypdf/commit/507d7c9aa6ea83389b954b9c3c0c528fe5d5da70
github.com/py-pdf/pypdf/pull/3791
github.com/py-pdf/pypdf/releases/tag/6.12.0
github.com/py-pdf/pypdf/security/advisories/GHSA-248m-82v9-q6g6
nvd.nist.gov/vuln/detail/CVE-2026-48156

Code Behaviors & Features

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