CVE-2026-42311

A vulnerability in Pillow before version 12.3.0 allows an attacker to read process memory or cause a fault when loading an uncompressed McIdas AREA image via the mmap codec path. Attacker-controlled header words can set a row stride smaller than the natural row width, leading to out-of-bounds read beyond the mapped region.

Integer overflow in the ImagingResampleHorizontal function in Pillow before version 3.1.1 allows remote attackers to have unspecified impact via negative values of the new size, leading to a heap-based buffer overflow.

In the Pillow Python imaging library, versions 5.1.0 through 12.3.0, the PdfParser.PdfStream.decode() function calls zlib.decompress() with a buffer size set to the PDF stream Length field without bounding the decompressed output size. This allows a crafted FlateDecode PDF stream to exhaust memory from a small file.

The Pillow library (Python Imaging Library) before version 12.3.0 contains a heap out-of-bounds write vulnerability in the public rank-filter API. Providing a very large odd filter size causes overflow in image dimension calculations.

A vulnerability in the Pillow Python imaging library allows controlled native heap corruption via the ImageCms.ImageCmsTransform.apply(im, imOut) API when the output image mode does not match the declared transform output mode. This issue is fixed in version 12.3.0.

Vulnerability in Pillow (versions 8.2.0 through 12.2.0) causes excessive memory usage when decoding a crafted tiled JPEG2000 file, potentially leading to denial of service (OOM).

Pillow library versions 12.0.0 through 12.2.0 have a vulnerability in the EPS parser (PIL/EpsImagePlugin.py) that allows an infinite loop via a crafted EPS file with a negative byte count in the %%BeginBinary directive. An attacker can exploit this to cause a denial of service (DoS) when opening a malicious file with Image.open().

A vulnerability in the Pillow Python imaging library allows a native heap out-of-bounds write when processing image coordinates near signed 32-bit integer limits in Image.paste(), Image.crop(), and Image.alpha_composite(). The issue is fixed in version 12.3.0.

In Pillow library versions 5.2.0 through 12.3.0, a vulnerability exists in the TGA RLE encoder. When saving a mode 1 image with RLE compression, the encoder reads past its packed row buffer, causing adjacent process heap bytes to be copied into the generated TGA file. The issue is fixed in version 12.3.0.

In Pillow prior to version 12.3.0, the WindowsViewer.get_command() function constructed a cmd.exe shell command by directly embedding a file path into an f-string without escaping and passed the result to subprocess.Popen(..., shell=True), allowing shell metacharacters in the file path to inject arbitrary cmd.exe commands.