Medium severity · published Oct 21, 2026
CVE-2026-113790
pypdf: Possible large memory usage when parsing arrays and dictionaries
6.0
CVSS
0.4%
EPSS
No
On KEV
Description
pypdf is a free and open-source pure-python PDF library. Prior to 6.21.0, an attacker can craft a PDF containing arrays or dictionaries with many elements, causing parsing to consume large amounts of memory. This issue is fixed in version 6.21.0.
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 33% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
PY
pypdf · py-pdf
< 6.21.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-113790
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-113790
github.com
https://github.com/py-pdf/pypdf/commit/18bd2981a74479483a0b9507602c58a63d6c9b12
github.com
https://github.com/py-pdf/pypdf/pull/4218
github.com
https://github.com/py-pdf/pypdf/releases/tag/6.21.0
github.com
https://github.com/py-pdf/pypdf/security/advisories/GHSA-f54x-cmq8-qg57
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