PYSEC-2026-4341

See a problem?
Import Source
https://github.com/pypa/advisory-database/blob/main/vulns/pillow/PYSEC-2026-4341.yaml
JSON Data
https://api.osv.dev/v1/vulns/PYSEC-2026-4341
Aliases
Published
2026-10-21T21:20:32Z
Modified
2026-10-28T11:00:02Z
Severity
  • 6.5 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H CVSS Calculator
Summary
[none]
Details

Pillow is a Python imaging library. Prior to 13.0.0, the TarIO initializer in src/PIL/TarIO.py accepts a negative octal member size and computes a backward seek that returns to the same 512-byte header. When the requested member name does not match, the parser repeatedly reads that header, consumes a full CPU core, and never returns. TarIO is reached only when an application directly uses PIL.TarIO.TarIO rather than the default Image.open() path. This issue is fixed in version 13.0.0.

References

Affected packages

PyPI / pillow

Package

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
13.0.0

Affected versions

1.*
1.0
1.1
1.2
1.3
1.4
1.5
1.6
1.7.0
1.7.1
1.7.2
1.7.3
1.7.4
1.7.5
1.7.6
1.7.7
1.7.8
2.*
2.0.0
2.1.0
2.2.0
2.2.1
2.2.2
2.3.0
2.3.1
2.3.2
2.4.0
2.5.0
2.5.1
2.5.2
2.5.3
2.6.0
2.6.1
2.6.2
2.7.0
2.8.0
2.8.1
2.8.2
2.9.0
3.*
3.0.0
3.1.0.rc1
3.1.0rc1
3.1.0
3.1.1
3.1.2
3.2.0
3.3.0
3.3.1
3.3.2
3.3.3
3.4.0
3.4.1
3.4.2
4.*
4.0.0
4.1.0
4.1.1
4.2.0
4.2.1
4.3.0
5.*
5.0.0
5.1.0
5.2.0
5.3.0
5.4.0.dev0
5.4.0
5.4.1
6.*
6.0.0
6.1.0
6.2.0
6.2.1
6.2.2
7.*
7.0.0
7.1.0
7.1.1
7.1.2
7.2.0
8.*
8.0.0
8.0.1
8.1.0
8.1.1
8.1.2
8.2.0
8.3.0
8.3.1
8.3.2
8.4.0
9.*
9.0.0
9.0.1
9.1.0
9.1.1
9.2.0
9.3.0
9.4.0
9.5.0
10.*
10.0.0
10.0.1
10.1.0
10.2.0
10.3.0
10.4.0
11.*
11.0.0
11.1.0
11.2.1
11.3.0
12.*
12.0.0
12.1.0
12.1.1
12.2.0
12.3.0

Database specific

source
"https://github.com/pypa/advisory-database/blob/main/vulns/pillow/PYSEC-2026-4341.yaml"