PYSEC-2026-3007 pypdf: Possible long runtimes for wrong size values in incremental mode

Impact An attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires loading a PDF with a large trailer /Size value in incremental mode. Patches This has been fixed in pypdf==6.10.2. Workarounds If you cannot upgrade yet, consider applying the changes from PR...

PYSEC-2026-3021 pypdf has long runtimes for wrong size values in cross-reference and object streams

Impact An attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires cross-reference streams with wrong large /Size values or object streams with wrong large /N values. Patches This has been fixed in pypdf==6.10.1. Workarounds If you cannot upgrade yet,...

PYSEC-2026-3012 pypdf: Possible infinite loop during recovery attempts in DictionaryObject.read_from_stream

Impact An attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires reading a file in non-strict mode. Patches This has been fixed in pypdf==6.9.2. Workarounds If users cannot upgrade yet, consider applying the changes from PR 3693...

PYSEC-2026-3023 pypdf has inefficient decoding of array-based streams

Impact An attacker who uses this vulnerability can craft a PDF which leads to long runtimes and/or large memory usage. This requires accessing an array-based stream with lots of entries. Patches This has been fixed in pypdf==6.9.1. Workarounds If you cannot upgrade yet, consider applying the...

PYSEC-2026-3019 pypdf: manipulated stream length values can exhaust RAM

Impact An attacker who uses this vulnerability can craft a PDF which leads to large memory usage. This requires parsing a content stream with a rather large /Length value, regardless of the actual data length inside the stream. Patches This has been fixed in pypdf==6.8.0. Workarounds If you canno...

PYSEC-2026-3014 pypdf vulnerable to inefficient decoding of ASCIIHexDecode 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 /ASCIIHexDecode filter. Patches This has been fixed in pypdf==6.7.5. Workarounds If you cannot upgrade yet, consider applying the changes from PR 3666...

PYSEC-2026-3017 pypdf: Manipulated RunLengthDecode streams can exhaust RAM

Impact An attacker who uses this vulnerability can craft a PDF which leads to large memory usage. This requires parsing the content stream using the RunLengthDecode filter. Patches This has been fixed in pypdf==6.7.4. Workarounds If you cannot upgrade yet, consider applying the changes from PR 36...

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...

PYSEC-2026-3005 pypdf has a possible infinite loop when loading circular /Prev entries in cross-reference streams

Impact An attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires reading the file. Patches This has been fixed in pypdf==6.7.2. Workarounds If users cannot upgrade yet, consider applying the changes from PR 3655...

PYSEC-2026-3024 pypdf has possible long runtimes/large memory usage for large /ToUnicode streams

Impact An attacker who uses this vulnerability can craft a PDF which leads to long runtimes and large memory consumption. This requires parsing the /ToUnicode entry of a font with unusually large values, for example during text extraction. Patches This has been fixed in pypdf==6.7.1. Workarounds ...

PYSEC-2026-3015 pypdf possibly has long runtimes for malformed FlateDecode streams

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...

PYSEC-2026-3008 pypdf and PyPDF2 possible Infinite Loop when a comment isn't followed by a character

Impact An attacker who uses this vulnerability can craft a PDF which leads to an infinite loop if parsecontentstream is executed. This infinite loop blocks the current process and can utilize a single core of the CPU by 100%. It does not affect memory usage. That is, for example, the case if the...

PT-2026-59644

Impact An attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires merging a file with outlines into a writer. Patches This has been fixed in pypdf==6.13.0. Workarounds If you cannot upgrade yet, consider applying the changes from PR 3830...

CVE-2026-59938

A flaw was found in pypdf, a free and open-source pure-python PDF library. An attacker can exploit this vulnerability by crafting a malicious PDF file with image size values that are significantly larger than the actual embedded image data, causing pypdf to allocate large amounts of memory when...

CVE-2026-59937

A flaw was found in pypdf, a pure-python PDF library. A remote attacker could exploit this vulnerability by crafting a malicious PDF file containing repeated malformed cross-reference streams. This could cause the pypdf library to spend excessive time recovering broken cross-reference table...

CVE-2026-59935

A flaw was found in pypdf, a pure-python PDF library. A remote attacker can craft a malicious PDF file containing an unterminated inline image within the page content stream. When this crafted PDF is parsed, it can lead to an infinite loop, resulting in a denial of service DoS due to resource...

SUSE CVE-2026-59938

pypdf is a free and open-source pure-python PDF library. Prior to 6.14.0, an attacker can craft a PDF with declared image size values that are much too large compared to the actual data, causing large memory usage in pypdf image parsing. This issue is fixed in version 6.14.0...

EUVD-2026-38358

pypdf: Possible infinite loop when processing threads/articles in writer...

GHSA-G9XF-7F8Q-9MCJ pypdf: Possible infinite loop when processing threads/articles in writer

Impact An attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires merging a file with threads/articles into a writer. Patches This has been fixed in pypdf==6.13.1. Workarounds If users cannot upgrade yet, consider applying the changes from PR 3839...

CVE-2026-59936

A flaw was found in pypdf, a pure-Python PDF library. A remote attacker can craft a malicious PDF document containing an unterminated inline image within its page content stream. When a user processes this crafted PDF, such as during text extraction, the vulnerability causes an infinite loop,...