High severity · published Oct 23, 2026
CVE-2026-115580
pypdf: Possible long runtimes for large xref table header limits
New
7.1
CVSS
0.4%
EPSS
No
On KEV
Description
pypdf is a free and open-source pure-python PDF library. Prior to 6.21.2, an attacker can craft a PDF with a standard cross-reference table whose declared entry count exceeds what the file can contain, causing excessive processing and long runtimes when the file is opened. This issue is fixed in version 6.21.2.
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 35% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
PY
pypdf · py-pdf
< 6.21.2 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-115580
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-115580
github.com
https://github.com/py-pdf/pypdf/commit/a3061e34b169d34478d520f5f049c53cfb1482b2
github.com
https://github.com/py-pdf/pypdf/pull/4239
github.com
https://github.com/py-pdf/pypdf/releases/tag/6.21.2
github.com
https://github.com/py-pdf/pypdf/security/advisories/GHSA-gmh7-3g9r-mjh5
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