CVSS 4.0
6.6 mediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:UCVE-2025-55197
Medium (6.6) in pypdf project pypdf. EPSS 0.5% chance of exploitation in the next 30 days. Fixed in pypdf 6.0.0.
pypdf is a free and open-source pure-python PDF library. Prior to version 6.0.0, an attacker 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 issue has been fixed in 6.0.0. If an update is not possible, a workaround involves including the fixed code from pypdf.filters.decompress into the existing filters file.
Severity
CVSS 3.1
7.5 highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H- EPSS
- 0.5% chance of exploitation in the next 30 days; higher than 41% of CVEs (scores of 2026-10-31)
- CWEs
- CWE-400, CWE-770
- Published
- Modified
- Record from
- the NVD, synced
Affected
- pypdf_project:pypdf
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-7hfw-26vp-jp8m | PyPI | pypdf | <6.0.0 | 6.0.0 |
| PYSEC-2026-1830 | PyPI | pypdf | <6.0.0 | 6.0.0 |
References
- https://github.com/py-pdf/pypdf/blob/0dd57738bbdcdb63f0fb43d8a6b3d222b6946595/pypdf/filters.py#L72-L143
- https://github.com/py-pdf/pypdf/issues/3429
- https://github.com/py-pdf/pypdf/pull/3430
- https://github.com/py-pdf/pypdf/releases/tag/6.0.0
- https://github.com/py-pdf/pypdf/security/advisories/GHSA-7hfw-26vp-jp8m