PYSEC-2026-1830

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Import Source
https://github.com/pypa/advisory-database/blob/main/vulns/pypdf/PYSEC-2026-1830.yaml
JSON Data
https://api.osv.dev/v1/vulns/PYSEC-2026-1830
Aliases
Published
2026-07-07T16:03:01.099738Z
Modified
2026-07-07T17:46:59.107811845Z
Severity
  • 6.6 (Medium) CVSS_V4 - CVSS: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:U CVSS Calculator
Summary
PyPDF's Manipulated FlateDecode streams can exhaust RAM
Details

Impact

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.

Patches

This has been fixed in pypdf==6.0.0.

Workarounds

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

References

This issue has been reported in #3429 and fixed in #3430.

References

Affected packages

PyPI / pypdf

Package

Name
pypdf
View open source insights on deps.dev
Purl
pkg:pypi/pypdf

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
6.0.0

Affected versions

1.*
1.0
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
1.10
1.11
1.12
1.13
3.*
3.1.0
3.2.0
3.2.1
3.3.0
3.4.0
3.4.1
3.5.0
3.5.1
3.5.2
3.6.0
3.7.0
3.7.1
3.8.0
3.8.1
3.9.0
3.9.1
3.10.0
3.11.0
3.11.1
3.12.0
3.12.1
3.12.2
3.13.0
3.14.0
3.15.0
3.15.1
3.15.2
3.15.3
3.15.4
3.15.5
3.16.0
3.16.1
3.16.2
3.16.3
3.16.4
3.17.0
3.17.1
3.17.2
3.17.3
3.17.4
4.*
4.0.0
4.0.1
4.0.2
4.1.0
4.2.0
4.3.0
4.3.1
5.*
5.0.0
5.0.1
5.1.0
5.2.0
5.3.0
5.3.1
5.4.0
5.5.0
5.6.0
5.6.1
5.7.0
5.8.0
5.9.0

Database specific

source 
"https://github.com/pypa/advisory-database/blob/main/vulns/pypdf/PYSEC-2026-1830.yaml"