CVE-2026-33699 PUBLISHED

pypdf: Possible infinite loop during recovery attempts in DictionaryObject.read_from_stream

Assigner: GitHub_M
Reserved: 23.03.2026 Published: 26.03.2026 Updated: 26.03.2026

pypdf is a free and open-source pure-python PDF library. Versions prior to 6.9.2 have a vulnerability in which an attacker can craft a PDF which leads to an infinite loop. This requires reading a file in non-strict mode. This has been fixed in pypdf 6.9.2. If users cannot upgrade yet, consider applying the changes from the patch manually.

Metrics

CVSS 4.0

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U
CVSS Score: 4.6

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

CVSS 4.0

Product Status

Vendor	py-pdf
Product	pypdf
Versions	Version < 6.9.2 is affected

References

Problem Types

CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop') CWE