High (7.8). EPSS 0.5% chance of exploitation in the next 30 days.
A heap-based buffer overflow exists in GNU Bash before 4.3 when wide characters, not supported by the current locale set in the LC_CTYPE environment variable, are printed through the echo built-in function. A local attacker, who can provide data to print through the "echo -e" built-in function, may use this flaw to crash a script or execute code with the privileges of the bash process. This occurs because ansicstr() in lib/sh/strtrans.c mishandles u32cconv().
Severity
CVSS 3.0
7.8 high
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS
0.5% chance of exploitation in the next 30 days; higher than 44% of CVEs (scores of 2026-10-31)