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.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
go-acme lego
< 4.34.0affected
References
- https://github.com/go-acme/lego/security/advisories/GHSA-qqx8-2xmm-jrv8 ↗
- https://access.redhat.com/security/cve/CVE-2026-40611 ↗
- https://bugzilla.redhat.com/show_bug.cgi?id=2460233 ↗
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-40611.json ↗
- https://access.redhat.com/errata/RHSA-2026:21772 ↗