{"id":"CVE-2025-55197","aliases":["GHSA-7hfw-26vp-jp8m","PYSEC-2026-1830"],"title":"PyPDF's Manipulated FlateDecode streams can exhaust RAM","summary":"PyPDF's Manipulated FlateDecode streams can exhaust RAM","severity":"medium","vendor":"pypdf","product":"pypdf","ecosystem":"pip","affected":["pypdf < 6.0.0"],"patched":["pypdf 6.0.0"],"published":"2025-08-13","updated":"2026-09-10","sourceUpdated":"2026-09-10T03:50:26.651449913Z","source":"OSV","sourceUrl":"https://osv.dev/vulnerability/GHSA-7hfw-26vp-jp8m","references":[{"url":"https://github.com/py-pdf/pypdf/security/advisories/GHSA-7hfw-26vp-jp8m"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2025-55197"},{"url":"https://github.com/py-pdf/pypdf/issues/3429"},{"url":"https://github.com/py-pdf/pypdf/pull/3430"},{"url":"https://github.com/py-pdf/pypdf"},{"url":"https://github.com/py-pdf/pypdf/blob/0dd57738bbdcdb63f0fb43d8a6b3d222b6946595/pypdf/filters.py#L72-L143"},{"url":"https://github.com/py-pdf/pypdf/releases/tag/6.0.0"}],"tags":["osv","pip"],"epss":0.00437,"epssPercentile":0.37478,"ingestedAt":"2026-07-08T18:25:47.010Z","slug":"CVE-2025-55197","body":"## Overview\n\n### Impact\nAn 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.\n\n### Patches\nThis has been fixed in [pypdf==6.0.0](https://github.com/py-pdf/pypdf/releases/tag/6.0.0).\n\n### Workarounds\nIf 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\n\n### References\nThis issue has been reported in #3429 and fixed in #3430.\n\n## Affected packages\n\n- `pypdf < 6.0.0`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `pypdf 6.0.0`","depth":"sunlit","depthScore":28,"depthScoreParts":{"impact":27.5,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}