pypdf and PyPDF2 possible Infinite Loop when a comment isn't followed by a character

ImpactAn 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...

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-2026-59642

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...

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-2026-59638

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

PT-2026-59628

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

PT-2026-59636

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...

PT-2026-59631

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...

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...

PT-2026-59632

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...

PT-2026-59626

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...

PT-2026-59640

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...

PT-2026-59635

Impact An attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires accessing the children of a TreeObject, for example as part of outlines. Patches This has been fixed in pypdf==6.7.1. Workarounds If you cannot upgrade yet, consider applying the changes...

PT-2026-59647

Impact 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. Patches This has been fixed in pypdf==6.12.1. Workarounds If you cannot upgrade yet, consider applying the change...

PT-2026-59646

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 ...

PT-2026-59633

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...

PT-2026-59643

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,...

PT-2026-59629

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...

PT-2026-59639

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...

PT-2026-59641

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...