Resource exhaustion in Traefik - CVE-2026-22045
Published: May 5, 2026
Vulnerability identifier: #VU129663
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-22045
CWE-ID: CWE-400
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Containous
Affected software:
Traefik
Traefik
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to uncontrolled resource consumption in ACME TLS-ALPN handling in pkg/server/router/tcp/router.go when processing stalled TLS-ALPN handshakes. A remote attacker can send a minimal ClientHello with acme-tls/1 and then stop responding to cause a denial of service.
Only entrypoints with the ACME TLS-ALPN challenge enabled and ACME bypass disabled are vulnerable.
How to mitigate CVE-2026-22045
Install security update from vendor's website.