Medium severity · published Apr 22, 2026
CVE-2026-41312
pypdf: Manipulated FlateDecode predictor parameters can exhaust RAM
6.5
CVSS
0.2%
EPSS
No
On KEV
Description
pypdf is a free and open-source pure-python PDF library. An attacker who uses a vulnerability present in versions prior to 6.10.2 can craft a PDF which leads to the RAM being exhausted. This requires accessing a stream compressed using `/FlateDecode` with a `/Predictor` unequal 1 and large predictor parameters. This has been fixed in pypdf 6.10.2. As a workaround, one may apply the changes from the patch manually.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 13% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
PY
pypdf · py-pdf
< 6.10.2 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-41312
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-41312
Patch
https://github.com/py-pdf/pypdf/commit/ac734dab4eef92bcce50d503949b4d9887d89f11
Issue Tracking
https://github.com/py-pdf/pypdf/pull/3734
Release Notes
https://github.com/py-pdf/pypdf/releases/tag/6.10.2
Patch
https://github.com/py-pdf/pypdf/security/advisories/GHSA-7gw9-cf7v-778f
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