An integer overflow in Pillow’s handling of PSD tile extents allows an attacker to write beyond buffer bounds, causing memory corruption. Such corruption can lead to a crash or, if an attacker can control the memory state, arbitrary code execution. The flaw is identified as CWE‑190 (Integer Overflow or Wraparound) and CWE‑787 (Out‑of‑Bounds Write).

The vulnerability affects the Pillow image library for Python, specifically versions from 10.3.0 up to and including 12.1.9. The patch was released in Pillow 12.2.0, which removes the unsafe handling of PSD tile extents.

The CVSS score of 8.6 denotes high severity. No EPSS score information is available, so the current exploitation probability cannot be quantified. The vulnerability is not listed in CISA’s KEV catalog. Based on the description, the attack vector is likely local or remote file processing; any process that loads a crafted PSD file with Pillow can trigger the overflow, potentially leading to code execution or denial of service.