Security Vulnerabilities
Pillow is a Python imaging library. Prior to 13.0.0, Pillow can double free image memory when ImagingScaleAffine encounters a selective allocation failure. The affected fast path handles Transform.EXTENT or pure scale-and-translate Transform.AFFINE operations with the default NEAREST resampling. The output image allocation must succeed while the additional per-column lookup allocation fails, after which the error path deletes image storage that later cleanup releases again. An attacker who can drive such a large Image.transform() operation under memory pressure may trigger the failure. This can crash the process and may corrupt memory. This issue is fixed in version 13.0.0.
CVSS Score
8.7
EPSS Score
0.006
Published
2026-10-19
Pillow is a Python imaging library. Prior to 13.0.0, Pillow's JPEG decoder can write a full-width scanline into a buffer sized for a requested draft scale. ImagingJpegDecode does not verify libjpeg's actual output width and component count after scaling is requested, and an 8-bit lossless SOF3 JPEG decoded by a build linked to libjpeg-turbo 3.x can ignore the requested downscaling geometry. An attacker can supply such a JPEG to an application that uses draft() or thumbnail() to request downscaling. This can corrupt heap memory, crash the process, or potentially allow code execution. Older libjpeg-turbo 2.x and IJG builds reject the SOF3 input. This issue is fixed in version 13.0.0.
CVSS Score
9.2
EPSS Score
0.009
Published
2026-10-19
Pillow is a Python imaging library. From 8.1.0 until 13.0.0, Pillow's TIFF tile and RGBA decode paths can read beyond row data produced by libtiff. In _decodeTile and the RGBA unpacker path, when Pillow and libtiff interpret duplicated PhotometricInterpretation or BitsPerSample tags differently, Pillow does not verify that the required input row fits inside the row libtiff produced, while the strip path has this validation. Loading pixels from such a crafted TIFF can expose adjacent heap data in output pixels or crash the process. This issue is fixed in version 13.0.0.
CVSS Score
8.8
EPSS Score
0.004
Published
2026-10-19
Pillow is a Python imaging library. Prior to 13.0.0, Pillow's rank-based filters can dereference invalid image storage for a zero-size image. ImagingExpand() allocates a non-empty output and then faults while replicating edges by reading the first pixel from empty input storage; ImagingRankFilter is never reached. An attacker can supply or cause creation of a zero-size image to an application that applies a rank, median, minimum, or maximum filter. This causes a native process crash. This issue is fixed in version 13.0.0.
CVSS Score
8.2
EPSS Score
0.006
Published
2026-10-19
Pillow is a Python imaging library. From 11.3.0 until 13.0.0, Pillow has a heap use-after-free when libtiff rejects a tag while encoding TIFF data to an in-memory buffer. When an application saves attacker-influenced TIFF tags to BytesIO, libtiff can reject a tag during encoding in ImagingLibTiffEncode; the error path then frees the output buffer without closing or clearing the TIFF handle, and later cleanup flushes through the write callback into freed memory, which can crash the process and may enable code execution. This issue is fixed in version 13.0.0.
CVSS Score
5.9
EPSS Score
0.007
Published
2026-10-19
Pillow is a Python imaging library. Prior to 13.0.0, Pillow's ImageMorph.MorphOp.apply() can access memory before a row buffer for a zero-width image. PPM and PGM input can create an image with width zero, and the native morphology routine indexes outrow[width - 1] without rejecting that geometry. An attacker can supply such an image to an application that applies a morphology operation. This can crash the process. This issue is fixed in version 13.0.0.
CVSS Score
8.7
EPSS Score
0.006
Published
2026-10-19
Pillow is a Python imaging library. From 7.2.0 until 13.0.0, Pillow can enter an infinite loop while determining the frame count of a MIC image. MicImageFile inherits TIFF frame traversal, but MicImageFile.tell reports the OLE stream index and its seek() resets TIFF frame state, so an embedded TIFF with at least three IFDs never advances. When an application with olefile installed reads n_frames or saves all frames from a crafted MIC file, the non-advancing traversal can hold a worker at full CPU indefinitely. This issue is fixed in version 13.0.0.
CVSS Score
8.2
EPSS Score
0.006
Published
2026-10-19
Pillow is a Python imaging library. From 5.1.0 until 13.0.0, Pillow's PdfParser.get_value() can recurse without a limit while reading nested PDF objects. The parser follows attacker-controlled arrays and dictionaries when an existing PDF is opened for append. An attacker can provide a deeply nested PDF to an application that saves an image with PDF append enabled. This can raise an uncaught RecursionError or terminate the worker, causing denial of service. This issue is fixed in version 13.0.0.
CVSS Score
6.3
EPSS Score
0.006
Published
2026-10-19
Pillow is a Python imaging library. From 2.0.0 until 13.0.0, Pillow has a heap buffer overflow and stale-heap disclosure in _tiffWriteProc when saving compressed TIFF data through libtiff to a target without a usable fileno(), such as BytesIO. The callback sizes its allocation from the prior buffer size instead of the current write position, allowing an attacker-controlled out-of-line TIFF tag or retained ICC profile to be copied beyond the allocation after libtiff seeks forward. This overflow can crash the process and may allow code execution. Independently, unwritten alignment gaps in compressed TIFF output larger than 64 KiB can disclose stale heap bytes without a crafted tag. File paths and targets with real file descriptors are unaffected. This issue is fixed in version 13.0.0.
CVSS Score
9.2
EPSS Score
0.01
Published
2026-10-19
Pillow is a Python imaging library. Prior to 13.0.0, Pillow's P;2L and P;4L raw decoders can read past the end of an input buffer. ImagingRawDecode calculates a packed-pixel row size, while the unpackers read separately padded bit planes. A caller can supply a buffer and image dimensions whose accepted size is smaller than the unpacker's actual footprint. This can disclose up to three adjacent heap bytes in output pixels or crash the process. This issue is fixed in version 13.0.0.
CVSS Score
6.3
EPSS Score
0.006
Published
2026-10-19