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CVE-2026-40611

NVD

https://nvd.nist.gov/vuln/detail/CVE-2026-40611

Severity

8.8

High

CVSS V3

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Summary

Lego: Arbitrary File Write via Path Traversal in Webroot HTTP-01 Provider

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

Affected packages

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