Pillow: Decompression Bomb DoS via PdfParser.PdfStream.decode()

SummaryPdfParser.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...

EUVD-2026-43753

Pillow: Decompression Bomb DoS via PdfParser.PdfStream.decode...

CVE-2026-59200

A flaw was found in Pillow, a Python imaging library. A remote attacker could exploit a vulnerability in the PdfParser.PdfStream.decode function when processing a crafted FlateDecode PDF stream. By providing a specially designed PDF file, the attacker could cause the application to exhaust...

CVE-2026-59200

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...

CVE-2026-59200

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...

CVE-2026-59200 Pillow: Decompression Bomb DoS via PdfParser.PdfStream.decode()

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...

CVE-2026-59200 Pillow: Decompression Bomb DoS via PdfParser.PdfStream.decode()

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...

CVE-2026-59200 Pillow: Decompression Bomb DoS via PdfParser.PdfStream.decode()

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...

CVE-2026-59200

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...

PYSEC-2026-3010 pypdf: Inefficient decoding of FlateDecode PNG predictor streams

Impact An attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires accessing a stream which uses the /FlateDecode filter with a PNG predictor. Patches This has been fixed in pypdf==6.12.2. Workarounds If you cannot upgrade yet, consider applying the changes...

PYSEC-2026-3026 pypdf: Manipulated FlateDecode image dimensions can exhaust RAM

Impact An attacker who uses this vulnerability can craft a PDF which leads to the RAM being exhausted. This requires accessing an image using /FlateDecode with large size values. Patches This has been fixed in pypdf==6.10.2. Workarounds If you cannot upgrade yet, consider applying the changes fro...

PYSEC-2026-3011 pypdf: Manipulated FlateDecode predictor parameters can exhaust RAM

Impact An attacker who uses this vulnerability can craft a PDF which leads to the RAM being exhausted. This requires accessing a stream compressed using /FlateDecode with a /Predictor unequal 1 and large predictor parameters. Patches This has been fixed in pypdf==6.10.2. Workarounds If you cannot...

PYSEC-2026-3027 pypdf: Manipulated FlateDecode XFA streams can exhaust RAM

Impact An attacker who uses this vulnerability can craft a PDF which leads to the RAM being exhausted. This requires accessing the xfa property of a reader or writer and the corresponding stream being compressed using /FlateDecode. Patches This has been fixed in pypdf==6.7.3. Workarounds If...

PT-2026-59649

Impact An attacker who uses this vulnerability can craft a PDF which leads to the RAM being exhausted. This requires accessing the xfa property of a reader or writer and the corresponding stream being compressed using /FlateDecode. Patches This has been fixed in pypdf==6.7.3. Workarounds If...

PT-2026-59637

Impact An attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires a malformed /FlateDecode stream, where the byte-by-byte decompression is used. Patches This has been fixed in pypdf==6.7.1. Workarounds If you cannot upgrade yet, consider applying the chang...

CVE-2026-49460

A flaw was found in pypdf before 6.12.2. A crafted PDF that accesses a stream using the /FlateDecode filter with a PNG predictor can trigger excessively long processing times, leading to denial of service when the document is parsed...

DEBIAN-CVE-2026-49460

pypdf is a free and open-source pure-python PDF library. Prior to 6.12.2, an attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires accessing a stream which uses the /FlateDecode filter with a PNG predictor. This vulnerability is fixed in 6.12.2...

CVE-2026-49460

pypdf is a free and open-source pure-python PDF library. Prior to 6.12.2, an attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires accessing a stream which uses the /FlateDecode filter with a PNG predictor. This vulnerability is fixed in 6.12.2...

CVE-2026-49460 pypdf: Inefficient decoding of FlateDecode PNG predictor streams

pypdf is a free and open-source pure-python PDF library. Prior to 6.12.2, an attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires accessing a stream which uses the /FlateDecode filter with a PNG predictor. This vulnerability is fixed in 6.12.2...

PT-2026-49729

Name of the Vulnerable Software and Affected Versions pypdf versions prior to 6.12.2 Description An attacker can craft a PDF file that results in long runtimes. This occurs when accessing a stream that utilizes the /FlateDecode filter with a PNG predictor. Recommendations Update to version 6.12.2...