CVE-2026-27628: pypdf has a possible infinite loop when loading circular /Prev entries in cross-reference streams

February 25, 2026

An attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires reading the file.

References

github.com/advisories/GHSA-2rw7-x74f-jg35
github.com/py-pdf/pypdf
github.com/py-pdf/pypdf/commit/f0a462d36971cf077d74492a348d0d06fd60ea4d
github.com/py-pdf/pypdf/issues/3654
github.com/py-pdf/pypdf/security/advisories/GHSA-2rw7-x74f-jg35
nvd.nist.gov/vuln/detail/CVE-2026-27628

Code Behaviors & Features

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