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...

pypdf: Possible infinite loop for not terminated inline images

ImpactAn attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires parsing the content stream of a page with a not terminated inline image, as done when extracting the page text for example. PatchesThis has been fixed in pypdf==6.14.1. WorkaroundsIf you...

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...

PYSEC-2026-3613 pypdf: Possible infinite loop for not terminated inline images (ASCII85 and ASCIIHex filter)

Impact An attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires parsing the content stream of a page with a not terminated inline image, as done when extracting the page text for example. It only affects the ASCII85 and ASCIIHex filters. Patches This...

PYSEC-2026-3611 pypdf: Possible large memory usage for wrong image dimensions

Impact An attacker who uses this vulnerability can craft a PDF which leads to large memory usage. This requires loading images where the declared size values are much too large compared to the actual data. Patches This has been fixed in pypdf==6.14.0. Workarounds If you cannot upgrade yet, consid...

Denial Of Service (DoS)

pypdf is vulnerable to Denial Of Service DoS. The vulnerability is due to inefficient recovery of malformed cross-reference streams in crafted PDF files, which allows an attacker to cause excessive processing time and trigger a denial-of-service condition...

GHSA-G867-7843-WF8Q pypdf: Possible infinite loop for not terminated inline images (ASCII85 and ASCIIHex filter)

Impact An attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires parsing the content stream of a page with a not terminated inline image, as done when extracting the page text for example. It only affects the ASCII85 and ASCIIHex filters. Patches This...

pypdf: Possible infinite loop for not terminated inline images

Impact An attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires parsing the content stream of a page with a not terminated inline image, as done when extracting the page text for example. Patches This has been fixed in pypdf==6.14.1. Workarounds If yo...

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...

EUVD-2026-42344

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

PYSEC-2026-3009 pypdf: Possible infinite loop when retrieving fonts for layout-mode text extraction

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

PYSEC-2026-3020 pypdf: Possible large memory usage for form XObjects during text extraction

Impact 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. Patches This has been fixed in pypdf==6.12.2. Workarounds If you cannot upgrade yet, consider applying...

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...

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

ImpactAn 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. PatchesThis has been fixed in pypdf==6.12.0. WorkaroundsIf developers are unable to upgrade their apps immediately, they...

pypdf: Manipulated FlateDecode predictor parameters can exhaust RAM

ImpactAn 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. PatchesThis has been fixed in pypdf==6.10.2. WorkaroundsIf you cannot...

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...

pypdf: Manipulated XMP metadata entity declarations can exhaust RAM

ImpactAn attacker who uses this vulnerability can craft a PDF which leads to large memory usage. This requires parsing the XMP metadata. PatchesThis has been fixed in pypdf==6.10.0. WorkaroundsIf you cannot upgrade yet, consider applying the changes from PR 3724...

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

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

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...