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PYSEC-2026-3010

pypdf: Inefficient decoding of FlateDecode PNG predictor streams

Quick fix

PYSEC-2026-3010 — pypdf: upgrade to the fixed version with the command below.

pip install --upgrade 'pypdf>=6.12.2'

Details

### Impact An attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires accessing a stream which uses the `/FlateDecode` filter with a PNG predictor.

### Patches This has been fixed in [pypdf==6.12.2](https://github.com/py-pdf/pypdf/releases/tag/6.12.2).

### Workarounds If you cannot upgrade yet, consider applying the changes from PR [#3806](https://github.com/py-pdf/pypdf/pull/3806).

Are you affected?

Enter the version of the package you're using.

Affected packages

PyPI/pypdf

Introduced in: 0Fixed in: 6.12.2

Fixpip install --upgrade 'pypdf>=6.12.2'

References

https://github.com/py-pdf/pypdf/security/advisories/GHSA-5hgr-hg42-57jg[WEB]
https://github.com/py-pdf/pypdf/pull/3806[WEB]
https://github.com/py-pdf/pypdf[PACKAGE]
https://github.com/py-pdf/pypdf/releases/tag/6.12.2[WEB]
https://pypi.org/project/pypdf[PACKAGE]
https://github.com/advisories/GHSA-5hgr-hg42-57jg[ADVISORY]
https://nvd.nist.gov/vuln/detail/CVE-2026-49460[ADVISORY]