Python Pillow vulnerabilities

CVE-2026-55798 Medium · 4.5 CWE-78 Jul 6, 2026

OS Command Injection in Python Pillow

Pillow is a Python imaging library. Prior to 12.3.0, WindowsViewer.get_command() 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. This issue is fixed in version 12.3.0.

CVE-2026-55380 High · 7.5 CWE-789 Jul 6, 2026

Pillow is a Python imaging library. Prior to 12.3.0, PIL/GdImageFile.py…

Pillow is a Python imaging library. Prior to 12.3.0, PIL/GdImageFile.py GdImageFile._open() read image dimensions from the GD 2.x header and stored them in self._size without calling Image._decompression_bomb_check(), allowing a crafted .gd file to trigger excessive C-heap allocation when loaded. This issue is fixed in version 12.3.0.

CVE-2026-55379 High · 7.5 CWE-789 Jul 6, 2026

Pillow is a Python imaging library. Prior to 12.3.0, PIL/BdfFontFile.py bdf_char() read…

Pillow is a Python imaging library. Prior to 12.3.0, PIL/BdfFontFile.py bdf_char() read the BBX width and height field from a BDF font file and passed attacker-controlled dimensions to Image.new() without calling Image._decompression_bomb_check(), bypassing Pillow's documented decompression bomb protection and allowing excessive memory allocation. This issue is fixed in version 12.3.0.

CVE-2026-54060 High · 7.5 CWE-789 Jul 6, 2026

Pillow is a Python imaging library. Prior to 12.3.0, PIL/FontFile.py FontFile.compile()…

Pillow is a Python imaging library. Prior to 12.3.0, PIL/FontFile.py FontFile.compile() assembled per-glyph images into a combined bitmap with Image.new("1", (xsize, ysize)) without calling Image._decompression_bomb_check(), allowing a font to trigger excessive allocation during conversion or saving. This issue is fixed in version 12.3.0.

CVE-2026-54059 High · 7.5 CWE-789 Jul 6, 2026

Pillow is a Python imaging library. Prior to 12.3.0, PIL/PcfFontFile.py _load_bitmaps()…

Pillow is a Python imaging library. Prior to 12.3.0, PIL/PcfFontFile.py _load_bitmaps() read glyph dimensions from the PCF METRICS section and passed them directly to Image.frombytes() without calling Image._decompression_bomb_check(), allowing crafted PCF font data to cause excessive memory allocation. This issue is fixed in version 12.3.0.

CVE-2026-42311 High · 7.8 CWE-190 May 9, 2026

Pillow: OOB Write with Invalid PSD Tile Extents (Integer Overflow)

Pillow is a Python imaging library. From version 10.3.0 to before version 12.2.0, processing a malicious PSD file could lead to memory corruption, potentially resulting in a crash or arbitrary code execution. This issue has been patched in version 12.2.0.

CVE-2026-42310 Medium · 5.5 CWE-835 May 9, 2026

Pillow: PDF Parsing Trailer Infinite Loop (DoS)

Pillow is a Python imaging library. From version 4.2.0 to before version 12.2.0, an attacker can supply a malicious PDF that causes the process to hang indefinitely, consuming 100% CPU and making the application unresponsive. This issue has been patched in version 12.2.0.

CVE-2026-42309 Medium · 5.5 CWE-122 May 9, 2026

Pillow: Heap buffer overflow with nested list coordinates

Pillow is a Python imaging library. From version 11.2.1 to before version 12.2.0, passing nested lists as coordinates to APIs that accept coordinates such as ImagePath.Path, ImageDraw.ImageDraw.polygon and ImageDraw.ImageDraw.line could cause a heap buffer overflow, as nested lists were recursively unpacked beyond the allocated buffer. Coordinate lists are now validated to contain exactly two numeric coordinates. This issue has been patched in version 12.2.0.

CVE-2026-42308 Medium · 5.5 CWE-190 May 9, 2026

Pillow: Integer overflow when processing fonts

Pillow is a Python imaging library. Prior to version 12.2.0, if a font advances for each glyph by an exceeding large amount, when Pillow keeps track of the current position, it may lead to an integer overflow. This issue has been patched in version 12.2.0.

CVE-2026-40192 High · 7.5 CWE-400 Apr 15, 2026

Pillow is vulnerable to a FITS GZIP decompression bomb

Pillow is a Python imaging library. Versions 10.3.0 through 12.1.1 did not limit the amount of GZIP-compressed data read when decoding a FITS image, making them vulnerable to decompression bomb attacks. A specially crafted FITS file could cause unbounded memory consumption, leading to denial of service (OOM crash or severe performance degradation). If users are unable to immediately upgrade, they should only open specific image formats, excluding FITS, as a workaround.

CVE-2026-25990 High · 7.5 CWE-787 Feb 11, 2026

Pillow has an out-of-bounds write when loading PSD images

Pillow is a Python imaging library. From 10.3.0 to before 12.1.1, an out-of-bounds write may be triggered when loading a specially crafted PSD image. This vulnerability is fixed in 12.1.1.