CVE-2025-55197Medium▾ SunlitPyPDF's Manipulated FlateDecode streams can exhaust RAM
▾ Sunlit zone — Low / medium · no exploitation signal
impact 27.5 · likelihood 0.1 · exploitation 0
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Exploit-prediction probability, daily snapshots since Jul 8.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via OSV
0.4%
0.4% → 0.4%
Last analysed / modified upstream
An attacker who uses this vulnerability can craft a PDF which leads to the RAM being exhausted. This requires just reading the file if a series of FlateDecode filters is used on a malicious cross-reference stream. Other content streams are affected on explicit access.
This has been fixed in pypdf==6.0.0.
If you cannot upgrade yet, you might want to implement the workaround for pypdf.filters.decompress yourself: https://github.com/py-pdf/pypdf/blob/0dd57738bbdcdb63f0fb43d8a6b3d222b6946595/pypdf/filters.py#L72-L143
This issue has been reported in #3429 and fixed in #3430.
pypdf < 6.0.0Upgrade to a patched release:
pypdf 6.0.0Connected by shared product, vendor, weakness, or advisory.
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