CVE-2026-54058

A flaw was found in Pillow prior to 12.3.0. When an uncompressed McIdas AREA image is loaded from a filename through the mmap raw codec path, attacker-controlled header words can set a row stride smaller than the natural row width. Pixel access such as Image.tobytes(), getpixel, convert, or save can then read beyond the mapped region, disclosing adjacent process memory or causing a fault.

Pillow is vulnerable to an out-of-bounds read when processing a crafted uncompressed McIdas AREA image via the mmap raw codec. A remote attacker who can supply such an image to a service that loads it without user interaction may disclose adjacent process memory or trigger a denial of service. Fixed in Pillow 12.3.0.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.