CVE-2026-119203: py-pdf pypdf

CVSS 7.1 (high) · published 2026-10-29

pypdf is a free and open-source pure-python PDF library. Prior to 6.21.4, pypdf can enter an infinite loop while opening a crafted incomplete PDF whose standard cross-reference table reaches the end of the file without a trailer. The trailer search can repeatedly rewind to the same stream position instead of terminating when parsing makes no progress, blocking the processing thread. This issue is fixed in version 6.21.4.

Affected products (NVD): py-pdf pypdf

Fixed in (NVD): 6.21.4

Weakness: CWE-835

Source: NVD CVE-2026-119203

References

• https://github.com/py-pdf/pypdf/commit/06593f993789a4b573dd955730c1a7051128bb2a
• https://github.com/py-pdf/pypdf/pull/4289
• https://github.com/py-pdf/pypdf/releases/tag/6.21.4
• https://github.com/py-pdf/pypdf/security/advisories/GHSA-5849-834g-hvw5

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