GHSA-23W6-3W8W-8484 pypdf: Possible long runtimes/large memory usage when retrieving outlines

Impact An attacker who uses this vulnerability can craft a PDF which leads to long runtimes and large memory consumption. This requires accessing the outlines of a document with either lots of entries or nested outlines with long re-used nesting paths. Patches This has been fixed in pypdf==6.16.1...

PYSEC-2026-3656 pypdf: Possible long runtimes/large memory usage for large CID font width ranges

Impact An attacker who uses this vulnerability can craft a PDF which leads to long runtimes and large memory consumption. This requires parsing the font width entries of a font with unusually large values, for example during text extraction. Patches This has been fixed in pypdf==6.15.0. Workaroun...

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

Impact An attacker who uses this vulnerability can craft a PDF which leads to long runtimes and large memory consumption. This requires parsing the font width entries of a font with unusually large values, for example during text extraction. Patches This has been fixed in pypdf==6.15.0. Workaroun...

CVE-2026-71852 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.collectcidcharacterwidths expands unusually large CID font /W width ranges or excessive width entries during text extractio...

CVE-2026-71852 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.collectcidcharacterwidths expands unusually large CID font /W width ranges or excessive width entries during text extractio...

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

ImpactAn attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires cross-reference streams with repeated malformed cross-reference streams. PatchesThis has been fixed in pypdf==6.14.0. WorkaroundsIf you cannot upgrade yet, consider applying the changes from ...

PYSEC-2026-3610 pypdf: Possible long runtimes for repeated malformed cross-reference entries

Impact An attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires cross-reference streams with repeated malformed cross-reference streams. Patches This has been fixed in pypdf==6.14.0. Workarounds If you cannot upgrade yet, consider applying the changes fr...

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

Impact An attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires cross-reference streams with repeated malformed cross-reference streams. Patches This has been fixed in pypdf==6.14.0. Workarounds If you cannot upgrade yet, consider applying the changes fr...

GHSA-55H5-XMCQ-C37V pypdf: Possible long runtimes for repeated malformed cross-reference entries

Impact An attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires cross-reference streams with repeated malformed cross-reference streams. Patches This has been fixed in pypdf==6.14.0. Workarounds If you cannot upgrade yet, consider applying the changes fr...

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...

pypdf: Inefficient decoding of FlateDecode PNG predictor streams

ImpactAn 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. PatchesThis has been fixed in pypdf==6.12.2. WorkaroundsIf you cannot upgrade yet, consider applying the changes fr...

PYSEC-2026-3004 pypdf: Possible long runtimes for zero-only width values in cross-reference streamsuntimes for zero-only width values in cross-reference streams

Impact 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. Patches This has been fixed in pypdf==6.12.0. Workarounds If developers are unable to upgrade their apps immediately, the...

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,...

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

ImpactAn 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. PatchesThis has been fixed in pypdf==6.10.1. WorkaroundsIf you cannot upgrade yet, consider...

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...

pypdf vulnerable to inefficient decoding of ASCIIHexDecode streams

ImpactAn attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires accessing a stream which uses the /ASCIIHexDecode filter. PatchesThis has been fixed in pypdf==6.7.5. WorkaroundsIf you cannot upgrade yet, consider applying the changes from PR 3666...

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...

pypdf possibly has long runtimes for malformed FlateDecode streams

ImpactAn 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. PatchesThis has been fixed in pypdf==6.7.1. WorkaroundsIf you cannot upgrade yet, consider applying the changes...

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 ...