Shescape before 2.1.15 (and 3.0.0 before 3.0.2) fails to properly escape tilde (~) characters in assignment contexts on Unix systems where the shell is explicitly configured to "sh" or true and /bin/sh points to BusyBox. Using the escape and escapeAll APIs with untrusted input in an assignment prefixed to a command, an attacker can inject a tilde payload to disclose the user's home directory location and, depending on usage, alter the location on which a command operates.
https://www.vulncheck.com/advisories/shescape-before-home-directory-disclosure-via-busybox
https://github.com/ericcornelissen/shescape/security/advisories/GHSA-j44h-fqhh-fh28
https://github.com/ericcornelissen/shescape/commit/d86bf2ae22961c73458bddf70dd06adf9dadb36c
https://github.com/ericcornelissen/shescape/commit/7cba30594c16a21524706efe2f6c6c9d8923f411
Published: 2026-08-15
Updated: 2026-08-15
Base Score: 4
Vector: CVSS2#AV:N/AC:H/Au:N/C:P/I:P/A:N
Severity: Medium
Base Score: 4.8
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
Severity: Medium
Base Score: 9.3
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Severity: Critical
EPSS: 0.00207