---
id: CVE-2023-47124
aliases:
  - GHSA-8g85-whqh-cr2f
  - GO-2023-2381
title: Traefik vulnerable to potential DDoS via ACME HTTPChallenge
summary: Traefik vulnerable to potential DDoS via ACME HTTPChallenge
severity: medium
cvss: 5.9
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'
vendor: traefik
product: github.com/traefik/traefik/v2
ecosystem: go
affected:
  - github.com/traefik/traefik/v2 < 2.10.6
  - github.com/traefik/traefik/v3 < 3.0.0-beta5
patched:
  - github.com/traefik/traefik/v2 2.10.6
  - github.com/traefik/traefik/v3 3.0.0-beta5
published: '2023-12-05'
updated: '2026-08-07'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GHSA-8g85-whqh-cr2f'
references:
  - url: 'https://github.com/traefik/traefik/security/advisories/GHSA-8g85-whqh-cr2f'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2023-47124'
  - url: 'https://doc.traefik.io/traefik/https/acme/#dnschallenge'
  - url: 'https://doc.traefik.io/traefik/https/acme/#httpchallenge'
  - url: 'https://doc.traefik.io/traefik/https/acme/#tlschallenge'
  - url: 'https://github.com/traefik/traefik'
  - url: 'https://github.com/traefik/traefik/releases/tag/v2.10.6'
  - url: 'https://github.com/traefik/traefik/releases/tag/v3.0.0-beta5'
  - url: 'https://www.cloudflare.com/learning/ddos/ddos-attack-tools/slowloris'
tags:
  - osv
  - go
epss: 0.00791
epssPercentile: 0.54813
ingestedAt: '2026-08-07T19:14:16.366Z'
---

## Overview

## Impact

There is a potential vulnerability in Traefik managing the ACME HTTP challenge.

When Traefik is configured to use the [HTTPChallenge](https://doc.traefik.io/traefik/https/acme/#httpchallenge) to generate and renew the Let's Encrypt TLS certificates, the delay authorized to solve the challenge (50 seconds) can be exploited by attackers ([slowloris attack](https://www.cloudflare.com/learning/ddos/ddos-attack-tools/slowloris/)).
 
## Patches

- https://github.com/traefik/traefik/releases/tag/v2.10.6
- https://github.com/traefik/traefik/releases/tag/v3.0.0-beta5

## Workarounds

Replace the HTTPChallenge with the [TLSChallenge](https://doc.traefik.io/traefik/https/acme/#tlschallenge) or the [DNSChallenge](https://doc.traefik.io/traefik/https/acme/#dnschallenge).

## For more information

If you have any questions or comments about this advisory, please [open an issue](https://github.com/traefik/traefik/issues).

## Affected packages

- `github.com/traefik/traefik/v2 < 2.10.6`
- `github.com/traefik/traefik/v3 < 3.0.0-beta5`

## Remediation

Upgrade to a patched release:

- `github.com/traefik/traefik/v2 2.10.6`
- `github.com/traefik/traefik/v3 3.0.0-beta5`