Medium severity · published Mar 10, 2026
CVE-2026-31826
pypdf: manipulated stream length values can exhaust RAM
5.5
CVSS
0.2%
EPSS
No
On KEV
Description
pypdf is a free and open-source pure-python PDF library. Prior to 6.8.0, an attacker who uses this vulnerability can craft a PDF which leads to large memory usage. This requires parsing a content stream with a rather large /Length value, regardless of the actual data length inside the stream. This vulnerability is fixed in 6.8.0.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Attack vector
Local
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 8% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
PY
pypdf · py-pdf
< 6.8.0 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-31826
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-31826
Issue Tracking
https://github.com/py-pdf/pypdf/pull/3675
Product
https://github.com/py-pdf/pypdf/releases/tag/6.8.0
Patch
https://github.com/py-pdf/pypdf/security/advisories/GHSA-hqmh-ppp3-xvm7
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