CVE-2026-96642 Pillow: TarIO negative size field causes infinite CPU-spin loop

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, consum...

CVE-2026-96642

The Pillow Python imaging library is vulnerable to an infinite CPU-spin loop in the TarIO initializer (located in src/PIL/TarIO.py) in versions prior to 13.0.0 . The root cause is the acceptance of a negative octal member size , which triggers a backward seek that returns to the same 512-byte hea...