Py-pdf Pypdf vulnerabilities

CVE-2026-84311 Low · 3.3 CWE-834 Sep 1, 2026

pypdf: Possible long runtimes/large memory usage when extracting XForm objects

pypdf is a free and open-source pure-python PDF library. Prior to 6.16.1, an attacker can craft a PDF that causes pypdf/_page.py PageObject._extract_text and PageObject.extract_xform_text to traverse a directed acyclic graph of reused form XObjects in which each form invokes a child multiple times, creating exponentially many traversal paths and causing long runtimes and large memory consumption. This issue is fixed in version 6.16.1.

CVE-2026-84310 Low · 3.3 CWE-405 Sep 1, 2026

pypdf: Possible long runtimes/large memory usage when retrieving outlines

pypdf is a free and open-source pure-python PDF library. Prior to 6.16.1, an attacker can craft a PDF that causes pypdf/_doc_common.py _get_outline to consume long runtimes and large amounts of memory when retrieving document outlines with large numbers of entries or deeply nested reused paths because the traversal lacked global entry-count and nesting-depth limits. This issue is fixed in version 6.16.1.

CVE-2026-84309 Medium · 5.5 CWE-835 Sep 1, 2026

pypdf: Possible infinite loop for TreeObject.insert_child

pypdf is a free and open-source pure-python PDF library. Prior to 6.16.0, an attacker can craft a PDF whose cyclic tree structure causes pypdf/generic/_data_structures.py TreeObject.insert_child to follow /Next links indefinitely when a writing code path inserts a child, producing an infinite loop. This issue is fixed in version 6.16.0.

CVE-2026-82398 Medium · 5.3 CWE-407 Aug 31, 2026

pypdf: Inefficient handling of non-whitespace inputs in read_until_whitespace

pypdf is a free and open-source pure-python PDF library. Prior to 6.15.0, an attacker can craft a PDF that causes long runtimes when the pypdf/_utils.py function read_until_whitespace reads a stream containing a long run of bytes without whitespace. The function repeatedly performs immutable bytes concatenation in a one-byte loop, causing quadratic processing cost for the long non-whitespace input. This issue is fixed in version 6.15.0.

CVE-2026-71870 Low · 3.3 CWE-400 Aug 7, 2026

pypdf: Possible large memory usage for large /ToUnicode streams

pypdf is a free and open-source pure-python PDF library. Prior to 6.15.0, a crafted PDF can cause large memory consumption when pypdf/_cmap.py function parse_bfrange parses unusually large source-code or destination-string tokens in a font /ToUnicode CMap during text extraction. This issue is fixed in 6.15.0.

CVE-2026-71852 Low · 3.3 CWE-834 Aug 7, 2026

pypdf: Possible long runtimes/large memory usage for large CID font width ranges

pypdf is a free and open-source pure-python PDF library. Prior to 6.15.0, a crafted PDF can cause long runtimes and large memory consumption when pypdf/_font.py function Font._collect_cid_character_widths expands unusually large CID font /W width ranges or excessive width entries during text extraction. This issue is fixed in 6.15.0.

CVE-2026-59936 High · 7.5 CWE-400 Jul 8, 2026

pypdf: Possible infinite loop for not terminated inline images

pypdf is a free and open-source pure-python PDF library. Prior to 6.14.1, an attacker can craft a PDF with a page content stream containing a not terminated inline image, causing an infinite loop during inline image end marker detection such as when extracting page text. This issue is fixed in version 6.14.1.

CVE-2026-59935 High · 7.5 CWE-835 Jul 8, 2026

pypdf: Possible infinite loop for not terminated inline images (ASCII85 and ASCIIHex filter)

pypdf is a free and open-source pure-python PDF library. Prior to 6.14.2, an attacker can craft a PDF with a page content stream containing a not terminated inline image that uses the ASCII85 or ASCIIHex filters, causing an infinite loop during parsing such as when extracting page text. This issue is fixed in version 6.14.2.

CVE-2026-59938 Medium · 5.3 CWE-789 Jul 8, 2026

pypdf: Possible large memory usage for wrong image dimensions

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.

CVE-2026-59937 High · 7.5 CWE-400 Jul 8, 2026

pypdf: Possible long runtimes for repeated malformed cross-reference entries

pypdf is a free and open-source pure-python PDF library. Prior to 6.14.0, an attacker can craft a PDF with repeated malformed cross-reference streams that cause pypdf to spend long runtimes recovering broken cross-reference table entries. This issue is fixed in version 6.14.0.

CVE-2026-57204 Medium · 6.5 CWE-400 Jun 30, 2026

pypdf: Missing stream length values ignore defined limits

pypdf is a free and open-source pure-python PDF library. Prior to 6.13.3, a maliciously crafted PDF can cause DoS. An attacker who uses this vulnerability can craft a PDF which leads to large memory usage, as MAX_DECLARED_STREAM_LENGTH is sometimes ignored. This requires parsing a content stream without a /Length value. This issue has been fixed in version 6.13.3.

CVE-2026-54651 Medium · 5.5 CWE-835 Jun 22, 2026

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

pypdf is a free and open-source pure-python PDF library. Prior to 6.13.1, 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. This vulnerability is fixed in 6.13.1.

CVE-2026-54531 Medium · 5.5 CWE-835 Jun 22, 2026

pypdf: Possible infinite loop when processing outlines/bookmarks in writer

pypdf is a free and open-source pure-python PDF library. Prior to 6.13.0, 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. This vulnerability is fixed in 6.13.0.

CVE-2026-54530 Medium · 5.5 CWE-835 Jun 22, 2026

pypdf: Possible infinite loop when retrieving fonts for layout-mode text extraction

pypdf is a free and open-source pure-python PDF library. Prior to 6.13.0, an attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires extracting the text in layout mode. This vulnerability is fixed in 6.13.0.

CVE-2026-49461 Medium · 5.5 CWE-400 Jun 22, 2026

pypdf: Possible large memory usage for form XObjects during text extraction

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 large memory usage. This requires extracting the text of a page which contains a form XObject with self-references. This vulnerability is fixed in 6.12.2.

CVE-2026-49460 Low · 3.3 CWE-407 Jun 22, 2026

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.

CVE-2026-48735 Medium · 5.5 CWE-770 May 28, 2026

pypdf: Manipulated XMP metadata streams can exhaust RAM

pypdf is a free and open-source pure-python PDF library. Prior to 6.12.1, an attacker who uses this vulnerability can craft a PDF which leads to large memory usage. This requires parsing large XMP metadata, possibly with lots of unnecessary elements. This vulnerability is fixed in 6.12.1.

CVE-2026-48156 Low · 3.3 CWE-834 May 28, 2026

pypdf: Possible long runtimes for zero-only width values in cross-reference streams

pypdf is a free and open-source pure-python PDF library. Prior to 6.12.0, an attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires cross-reference streams with /W [0 0 0] values and large /Size values. This vulnerability is fixed in 6.12.0.

CVE-2026-48155 Medium · 5.5 CWE-400 May 28, 2026

pypdf: Possible large memory usage for large offsets for layout mode text

pypdf is a free and open-source pure-python PDF library. Prior to 6.12.0, an attacker who uses this vulnerability can craft a PDF which leads to large memory usage. This requires extracting text in layout mode with large character offsets. This vulnerability is fixed in 6.12.0.

CVE-2026-41314 Medium · 6.5 CWE-789 Apr 22, 2026

pypdf: Manipulated FlateDecode image dimensions can exhaust RAM

pypdf is a free and open-source pure-python PDF library. An attacker who uses a vulnerability present in versions prior to 6.10.2 can craft a PDF which leads to the RAM being exhausted. This requires accessing an image using `/FlateDecode` with large size values. This has been fixed in pypdf 6.10.2. As a workaround, one may apply the changes from the patch manually.

CVE-2026-41313 Medium · 6.5 CWE-834 Apr 22, 2026

pypdf: Possible long runtimes for wrong size values in incremental mode

pypdf is a free and open-source pure-python PDF library. An attacker who uses a vulnerability present in versions prior to 6.10.2 can craft a PDF which leads to long runtimes. This requires loading a PDF with a large trailer `/Size` value in incremental mode. This has been fixed in pypdf 6.10.2. As a workaround, one may apply the changes from the patch manually.

CVE-2026-41312 Medium · 6.5 CWE-789 Apr 22, 2026

pypdf: Manipulated FlateDecode predictor parameters can exhaust RAM

pypdf is a free and open-source pure-python PDF library. An attacker who uses a vulnerability present in versions prior to 6.10.2 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. This has been fixed in pypdf 6.10.2. As a workaround, one may apply the changes from the patch manually.

CVE-2026-41168 Medium · 5.3 CWE-834 Apr 22, 2026

pypdf has possible long runtimes for wrong size values in cross-reference and object streams

pypdf is a free and open-source pure-python PDF library. An attacker who uses a vulnerability present in versions prior to 6.10.1 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. This has been fixed in pypdf 6.10.1. As a workaround, one may apply the changes from the patch manually.

CVE-2026-40260 Medium · 5.3 CWE-776 Apr 16, 2026

pypdf: Manipulated XMP metadata entity declarations can exhaust RAM

pypdf is a free and open-source pure-python PDF library. In versions prior to 6.10.0, manipulated XMP metadata entity declarations can exhaust RAM. An attacker who exploits this vulnerability can craft a PDF which leads to large memory usage. This requires parsing the XMP metadata. This issue has been fixed in version 6.10.0.

CVE-2026-33699 High · 7.5 CWE-835 Mar 26, 2026

pypdf: Possible infinite loop during recovery attempts in DictionaryObject.read_from_stream

pypdf is a free and open-source pure-python PDF library. Versions prior to 6.9.2 have a vulnerability in which an attacker can craft a PDF which leads to an infinite loop. This requires reading a file in non-strict mode. This has been fixed in pypdf 6.9.2. If users cannot upgrade yet, consider applying the changes from the patch manually.