BIT-PILLOW-2026-112894 Pillow: Quadratic-time DoS in PDF save_all (PdfParser.next_object_id)

Pillow is a Python imaging library. From 5.1.0 until 13.0.0, Pillow takes quadratic time to reserve PDF object identifiers when saving many frames with saveall enabled. PdfParser.nextobjectid repeatedly rebuilds and scans all previously reserved identifiers for every object. An attacker can suppl...

BIT-PILLOW-2026-112893 Pillow: Invalid free in FreeType glyph rendering when a stroker is active

Pillow is a Python imaging library. From 10.0.0 until 13.0.0, Pillow can free an invalid glyph pointer during FreeType rendering with an active stroker. If FTLoadGlyph fails, cleanup may call FTDoneGlyph on an uninitialized or stale glyph variable. An attacker can supply a malformed font as...

BIT-PILLOW-2026-112892 Pillow: MSP RLE decoder expands a tiny file into unbounded memory

Pillow is a Python imaging library. From 4.1.0 until 13.0.0, Pillow's MSP RLE decoder can expand a small file into an unbounded in-memory buffer. The decoder writes run-length output to BytesIO without limiting expansion to the declared image size. An attacker can supply a crafted MSP image to an...

BIT-PILLOW-2026-112891 Pillow: Quadratic GIF comment copying during save

Pillow is a Python imaging library. From 9.2.0 until 13.0.0, Pillow performs quadratic copying when saving a GIF with a long comment. getglobalheader repeatedly copies portions of comment data while assembling the global header, including comments retained from an untrusted input image. An attack...

BIT-PILLOW-2026-112406 Pillow: Infinite loop in PdfParser.rewrite_pages on page tree Parent cycle

Pillow is a Python imaging library. From 5.1.0 until 13.0.0, Pillow can enter an infinite loop while rewriting PDF pages. PdfParser.rewritepages follows Parent relationships without detecting a cycle in the page tree. An attacker can supply a cyclic PDF to an application that appends an image to...

BIT-PILLOW-2026-112405 Pillow: NULL pointer dereference in Image.merge via an unvalidated band 0

Pillow is a Python imaging library. From 12.0.0 until 13.0.0, Pillow's Image.merge can dereference a null image8 plane. Validation skips the first input band, allowing a 32-bit integer or floating-point image backed by image32 storage to be merged as a narrower multiband image. A crafted IPTC fil...

BIT-PILLOW-2026-112404 Pillow: OOB read in TiffDecode.c tile and RGBA paths leaks heap memory into pixels

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,...

BIT-PILLOW-2026-112403 Pillow: Heap buffer overflow in ImagingJpegDecode

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 JP...

BIT-PILLOW-2026-112402 Pillow: Double free in ImagingScaleAffine on calloc failure via Image.transform

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...

BIT-PILLOW-2026-112401 Pillow: Quadratic GIF comment concatenation allows DoS in Image.open()

Pillow is a Python imaging library. From 5.4.0 until 13.0.0, Pillow performs quadratic copying while parsing GIF comments. GifImageFile.seek repeatedly appends immutable bytes for comment sub-blocks and multiple comment extensions, and frame zero is parsed during Image.open. An attacker can submi...

BIT-PILLOW-2026-112400 Pillow: GIF seek keeps rejected size after DecompressionBombError, allowing DoS

Pillow is a Python imaging library. From 9.2.0 until 13.0.0, Pillow can retain a rejected GIF frame size after a decompression-bomb exception. In GifImageFile.seek, a crafted GIF can leave rejected dimensions stored after Image.DecompressionBombError; if an application catches that exception and...

BIT-PILLOW-2026-112399 Pillow: APNG background disposal allocates full canvas before decompression bomb check

Pillow is a Python imaging library. From 8.1.0 until 13.0.0, Pillow can allocate an APNG disposal background at the full canvas size before applying the decompression-bomb check. A crafted APNG with a small first frame, a very large declared canvas, and background disposal or first-frame OPPREVIO...

BIT-PILLOW-2026-112398 Pillow: Heap buffer overflow in FlashPix (FPX) JPEG decoding leads to code execution

Pillow is a Python imaging library. Prior to 13.0.0, Pillow's FlashPix JPEG-tile decoder can write decoded scanlines beyond the allocated tile buffer. FlashPix FPX JPEG decoding selects raw mode LA with two bytes per pixel, while an unrecognized JPEG mode can be decoded as JCSUNKNOWN with four...

BIT-PILLOW-2026-112397 Pillow: Out-of-bounds access in _imagingmorph on a zero-width image

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 outrowwidth - 1 without rejecting that geometry. An...

BIT-PILLOW-2026-112396 Pillow: Heap use-after-free when encoding TIFF to an in-memory buffer

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...

BIT-PILLOW-2026-112395 Pillow tiled-TIFF decoder reads past tile buffer in copy4 (Unpack.c:1290)

Pillow is a Python imaging library. From 8.2.0 until 13.0.0, Pillow's tiled-TIFF decoder can read past the tile buffer while copying four-byte pixels. In decodeTile, libtiff can return a tile allocation smaller than the required row stride multiplied by the tile length, and Pillow's stride-and-co...

BIT-PILLOW-2026-112394 Pillow: P;2L and P;4L decoders may read 1 to 3 bytes past the passed buffer size

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...

BIT-PILLOW-2026-112393 Pillow: Heap buffer overflow in _tiffWriteProc when saving TIFF to BytesIO

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...

BIT-PILLOW-2026-112392 Pillow: NULL dereference in ImagingExpand via rank filters on zero-size images

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 i...

BIT-PILLOW-2026-112391 Pillow: PdfParser can recurse without limit in get_value() and linearize_page_tree()

Pillow is a Python imaging library. From 5.1.0 until 13.0.0, Pillow's PdfParser.getvalue 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...