Detections
Analytics
CVE-2026-40611
high
Description
Let's Encrypt client and ACME library written in Go (Lego). Prior to 4.34.0, the webroot HTTP-01 challenge provider in lego is vulnerable to arbitrary file write and deletion via path traversal. A malicious ACME server can supply a crafted challenge token containing ../ sequences, causing lego to write attacker-influenced content to any path writable by the lego process. This vulnerability is fixed in 4.34.0.
References
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-40611.json
https://github.com/go-acme/lego/security/advisories/GHSA-qqx8-2xmm-jrv8
https://bugzilla.redhat.com/show_bug.cgi?id=2460233