pypdf is a free and open-source pure-python PDF library. Prior to 6.12.2, an attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires accessing a stream which uses the /FlateDecode filter with a PNG predictor. This vulnerability is fixed in 6.12.2.
https://github.com/py-pdf/pypdf/security/advisories/GHSA-5hgr-hg42-57jg
Published: 2026-06-22
Updated: 2026-06-25
Base Score: 1.7
Vector: CVSS2#AV:L/AC:L/Au:S/C:N/I:N/A:P
Severity: Low
Base Score: 3.3
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
Severity: Low
Base Score: 5.1
Vector: 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
Severity: Medium
EPSS: 0.00024