Medium severity · published Oct 21, 2026
CVE-2026-113789
pypdf: Possible long runtimes/large memory usage when retrieving form fields
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 that causes large memory usage or long runtimes when an application retrieves the document's form fields. 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-2026-113789
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-113789
github.com
https://github.com/py-pdf/pypdf/commit/5ef728f0e16d225c853e89f861ba0a67402fe3f2
github.com
https://github.com/py-pdf/pypdf/pull/4219
github.com
https://github.com/py-pdf/pypdf/releases/tag/6.21.0
github.com
https://github.com/py-pdf/pypdf/security/advisories/GHSA-6vvc-x485-93v7
More from pypdf
7.5
CVE-2026-103000
pypdf: Possible large memory usage when retrieving alphabetical page labels
7.5
CVE-2026-102999
pypdf: Possible long runtimes with large amount of embedded files
7.5
CVE-2026-102998
pypdf: Possible long runtimes when generating appearance streams
7.5
CVE-2026-102997
pypdf: Possible long runtimes for partially malformed FlateDecode streams (Follow-up)
7.5
CVE-2026-102996
pypdf: Possible large memory usage when parsing font data