CVE-2023-40185: Shescape on Windows escaping may be bypassed in threaded context

Severity: high (CVSS 8.6 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.7% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2023-08-23 · updated 2026-06-17
Weakness: CWE-150

Description

shescape is simple shell escape library for JavaScript. This may impact users that use Shescape on Windows in a threaded context. The vulnerability can result in Shescape escaping (or quoting) for the wrong shell, thus allowing attackers to bypass protections depending on the combination of expected and used shell. This bug has been patched in version 1.7.4.

Affected products

ericcornelissen shescape: before 1.7.4 — fixed in 1.7.4

How to fix

Upgrade to a fixed version: ericcornelissen shescape 1.7.4. Check the vendor advisory for mitigations.

References

https://github.com/ericcornelissen/shescape/commit/0b976dab645abf45ffd85e74a8c6e51ee2f42d63
https://github.com/ericcornelissen/shescape/pull/1142
https://github.com/ericcornelissen/shescape/releases/tag/v1.7.4
https://github.com/ericcornelissen/shescape/security/advisories/GHSA-j55r-787p-m549
https://github.com/ericcornelissen/shescape/commit/0b976dab645abf45ffd85e74a8c6e51ee2f42d63
https://github.com/ericcornelissen/shescape/pull/1142
https://github.com/ericcornelissen/shescape/releases/tag/v1.7.4
https://github.com/ericcornelissen/shescape/security/advisories/GHSA-j55r-787p-m549

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