CVE-2021-43312: Upx

High severity, CVSS 7.5. EPSS: 0.8% chance of exploitation in the next 30 days.

A heap-based buffer overflow was discovered in upx, during the variable 'bucket' points to an inaccessible address. The issue is being triggered in the function PackLinuxElf64::invert_pt_dynamic at p_lx_elf.cpp:5239.

Affected products

• Upx Upx: before 4.0.0 (fixed in 4.0.0)

Published 2023-03-24. Last modified 2026-06-17.