CVE-2026-96642: CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop') in python-pillow Pillow
Description
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.
CVSS v4.0
Score 7.1high
Affected software
python-pillow
Pillow
Weaknesses
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-09-23T14:35:50.130Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6ad928464d27ba8daa01072d
Added to database: 10/21/2026, 21:01:58 UTC
Last updated: 10/21/2026, 21:01:58 UTC
Views: 1
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