CVE-2026-119203

Description

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.

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Weakness Type (CWE)

CWE-835 CWE-835

References

Other 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

Frequently Asked Questions

What is CVE-2026-119203? +

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.

How do I check if I'm vulnerable to CVE-2026-119203? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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