pypdf is a free and open-source pure-python PDF library. Prior to 6.12.0, an attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires cross-reference streams with /W [0 0 0] values and large /Size values. This vulnerability is fixed in 6.12.0.
https://github.com/py-pdf/pypdf/security/advisories/GHSA-248m-82v9-q6g6
Published: 2026-05-28
Updated: 2026-05-29
Base Score: 2.1
Vector: CVSS2#AV:L/AC:L/Au:N/C:N/I:N/A:P
Severity: Low
Base Score: 3.3
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/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: 0.00013