CVE-2021-26843: Sthttpd Project Sthttpd

High severity, CVSS 7.5. EPSS: 1.4% chance of exploitation in the next 30 days.

An issue was discovered in sthttpd through 2.27.1. On systems where the strcpy function is implemented with memcpy, the de_dotdot function may cause a Denial-of-Service (daemon crash) due to overlapping memory ranges being passed to memcpy. This can triggered with an HTTP GET request for a crafted filename. NOTE: this is similar to CVE-2017-10671, but occurs in a different part of the de_dotdot function.

Affected products

• Sthttpd Project Sthttpd: up to and including 2.27.1

Published 2021-02-07. Last modified 2026-06-17.