CVE-2026-96642
Pillow: TarIO negative size field causes infinite CPU-spin loop
- State
- Published
- Severity
- 7.1 High
- Published
- Oct 21, 2026
- Updated
- Oct 30, 2026
- Reserved
- Sep 23, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 7.1 High | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N | GitHub_M |
Weaknesses
- CWE-835 Loop with Unreachable Exit Condition ('Infinite Loop')
Affected Products
| Product | Versions |
|---|---|
Pillowpython-pillow |
|
References
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