CVE-2026-113786: py-pdf pypdf Improper Input Validation
CVSS: 2.3v4.0LowReceived
AliasesGHSA-5hx5-vpf9-5wcv
Published 21-10-2026Last modified 21-10-2026
Vulnerability summary
CVE-2026-113786 is a low (CVSS 2.3) Improper Input Validation vulnerability in py-pdf pypdf.
CVSS score
2.3/10
010
Low · v4.0 (CVE.org)EPSS score
Not scored
0%100%
No EPSS score yetKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Timeline
- 21-10-2026PublishedVulnerability first disclosed.
Description
pypdf is a free and open-source pure-python PDF library. Prior to 6.21.1, an attacker can craft a PDF containing image data labeled with the /DCTDecode filter that causes Pillow to select and invoke an unintended image parser when the image is loaded. Environments without the optional Pillow dependency are not affected. This issue is fixed in version 6.21.1.
CVSS metrics
3 scores · 3 sources · 1 versionLow 2.3Preferred score · CVE.org (CNA)
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:NSourcesAll 3 agree
- NVDNIST2.3LowCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- OSV · PypiEcosystem advisory · calculated2.3LowCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
EPSS trend
No EPSS score has been published for this record yet.
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-20Improper Input ValidationThe product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
- CWE-183Permissive List of Allowed InputsThe product implements a protection mechanism that relies on a list of inputs (or properties of inputs) that are explicitly allowed by policy because the inputs are assumed to be safe, but the list is too permissive - that is, it allows an input that is unsafe, leading to resultant weaknesses.
Affected systems
Py-pdf1 product
- pypdf< 6.21.1
PyPI1 product
- pypdf< 6.21.1
2 vendors · 2 products
References
6 links
- github.com/py-pdf/pypdfPACKAGE