High severity · published Oct 29, 2026
CVE-2026-119203
pypdf: Possible infinite loop when hitting EOF in standard xref table during trailer search
New
7.1
CVSS
–
EPSS
No
On KEV
Description
pypdf is a free and open-source pure-python PDF library. Prior to 6.21.4, pypdf can enter an infinite loop while opening a crafted incomplete PDF whose standard cross-reference table reaches the end of the file without a trailer. The trailer search can repeatedly rewind to the same stream position instead of terminating when parsing makes no progress, blocking the processing thread. This issue is fixed in version 6.21.4.
Exploitation
Is it being used?
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
PY
pypdf · py-pdf
< 6.21.4 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-119203
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-119203
github.com
https://github.com/py-pdf/pypdf/commit/06593f993789a4b573dd955730c1a7051128bb2a
github.com
https://github.com/py-pdf/pypdf/pull/4289
github.com
https://github.com/py-pdf/pypdf/releases/tag/6.21.4
github.com
https://github.com/py-pdf/pypdf/security/advisories/GHSA-5849-834g-hvw5
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