CVE-2026-31826 PUBLISHED

pypdf: manipulated stream length values can exhaust RAM

Assigner: GitHub_M
Reserved: 09.03.2026 Published: 10.03.2026 Updated: 10.03.2026

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.

Metrics

CVSS 4.0

CVSS Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CVSS Score: 6.8

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Local	Confidentiality	None	Confidentiality	None
Attack Complexity	Low	Integrity	None	Integrity	None
Attack Requirements	None	Availability	High	Availability	None
Privileges Required	None
User Interaction	Passive

CVSS 4.0

Product Status

Vendor	py-pdf
Product	pypdf
Versions	Version < 6.8.0 is affected

References

Problem Types

CWE-770: Allocation of Resources Without Limits or Throttling CWE