High severity · published Sep 30, 2026
CVE-2026-103000
pypdf: Possible large memory usage when retrieving alphabetical page labels
7.5
CVSS
0.4%
EPSS
No
On KEV
Description
pypdf is a free and open-source pure-python PDF library. Prior to 6.19.0, a crafted PDF can provide unusually large alphabetical page-label values that cause pypdf/_page_labels.py to generate strings beyond a reasonable page-label length when an application retrieves document page labels, consuming excessive memory and potentially making the application unavailable. This issue is fixed in version 6.19.0.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 29% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
PY
pypdf · py-pdf
< 6.19.0 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-103000
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-103000
x_refsource_CONFIRM
https://github.com/py-pdf/pypdf/security/advisories/GHSA-w23x-9jrw-r45c
x_refsource_MISC
https://github.com/py-pdf/pypdf/pull/4096
x_refsource_MISC
https://github.com/py-pdf/pypdf/commit/0d8b5a8832cde1ba308b5c27567b879b7b7eed4a
x_refsource_MISC
https://github.com/py-pdf/pypdf/releases/tag/6.19.0
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