CVE-2026-22045CWE-770

Traefik's ACME TLS-ALPN fast path lacks timeouts and close on handshake stall

Medium · published January 15, 2026

CVSS v3.1
5.9
EPSS
0%
Percentile
26.5
In the wild
Unconfirmed
What it is

Traefik is an HTTP reverse proxy and load balancer. Prior to 2.11.35 and 3.6.7, there is a potential vulnerability in Traefik ACME TLS certificates' automatic generation: the ACME TLS-ALPN fast path can allow unauthenticated clients to tie up go routines and file descriptors indefinitely when the ACME TLS challenge is enabled. A malicious client can open many connections, send a minimal ClientHello with acme-tls/1, then stop responding, leading to denial of service of the entry point. The vulnerability is fixed in 2.11.35 and 3.6.7.

The record
Technical detail
CVSS v3.1
5.9 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00343 · 26.5th percentile
Weakness
CWE-770 · Allocation of Resources Without Limits or Throttling
Published
2026-01-15T22:44Z
EPSS history
Timeline
  • 15 JAN 22:44Z
    Traefik's ACME TLS-ALPN fast path lacks timeouts and close on handshake stall
    cvelistv5