← back
CVE-2026-33123mediumCWE-400CWE-407

pypdf has inefficient decoding of array-based streams

13Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 5.1epss 0.3%
exploitation probability
0.3%top 72% of all CVEs
observed exploitation
nono source reports it
pypdf is a free and open-source pure-python PDF library. Versions prior to 6.9.1 allow an attacker to craft a malicious PDF which leads to long runtimes and/or large memory usage. Exploitation requires accessing an array-based stream with many entries. This issue has been fixed in version 6.9.1.
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
Affected products
py-pdf · pypdf