CVE-2026-40611 | BDVDB-2026-328124 Detail

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.

Impact#

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Exploit#

History#

1. Version 12026-04-21Record published in the CVE List.
2. Version 22026-07-15Most recent update recorded in the CVE List.