Medium severity · published Jun 30, 2026
CVE-2026-57204
pypdf: Missing stream length values ignore defined limits
6.5
CVSS
0.4%
EPSS
No
On KEV
Description
pypdf is a free and open-source pure-python PDF library. Prior to 6.13.3, a maliciously crafted PDF can cause DoS. An attacker who uses this vulnerability can craft a PDF which leads to large memory usage, as MAX_DECLARED_STREAM_LENGTH is sometimes ignored. This requires parsing a content stream without a /Length value. This issue has been fixed in version 6.13.3.
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)0.4% · higher than 30% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
PY
pypdf · py-pdf
< 6.13.3 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-57204
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-57204
Product
https://github.com/py-pdf/pypdf/releases/tag/6.13.3
Patch
https://github.com/py-pdf/pypdf/security/advisories/GHSA-jm82-fx9c-mx94
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