CVE-2026-102998
pypdf is a free and open-source pure-python PDF library. Prior to 6.19.0, a crafted PDF with form field values can cause pypdf/generic/_appearance_stream.py appearance-stream generation to repeat invariant selection-data work inside a loop when an application updates fields with flattening enabled, resulting in excessive runtimes and application unavailability. This issue is fixed in version 6.19.0.
- Published Sep 30, 2026
- CVSS 8.7 high
- 0.3% chance of exploitation in the next 30 days (EPSS)
- A fix is available