TI-2026-17739 Aliases CVE-2026-22045 GHSA-cwjm-3f7h-9hwq

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

LOW 33CWE-770Published 2026-01-15 · Updated 2026-01-20

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · High
Fix status: Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-770.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00343 27th percentileScored 2026-11-07

Fix Fixed traefik (traefik): 2.11.35, 3.6.7github.com/traefik/traefik/v3 (Go): 3.6.7+1 more productRed Hat: 1 advisory

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
traefik	traefik	before 2.11.35; 3.0.0-beta1 to before 3.6.7	2.11.35, 3.6.7	Patch available	CNA
—	github.com/traefik/traefik/v3 (Go)	before 3.6.7	3.6.7	Patch available	GHSA-cwjm-3f7h-9hwq
—	github.com/traefik/traefik/v2 (Go)	before 2.11.35	2.11.35	Patch available	GHSA-cwjm-3f7h-9hwq

traefik Vendortraefik Affected before 2.11.35; 3.0.0-beta1 to before 3.6.7 Fixed in 2.11.35, 3.6.7 Patch available CNA
github.com/traefik/traefik/v3 (Go) Vendor— Affected before 3.6.7 Fixed in 3.6.7 Patch available GHSA-cwjm-3f7h-9hwq
github.com/traefik/traefik/v2 (Go) Vendor— Affected before 2.11.35 Fixed in 2.11.35 Patch available GHSA-cwjm-3f7h-9hwq

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:traefik:traefik::::::::	before 2.11.35; 3.0.0 to before 3.6.7	Vulnerable	traefik

cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:* Versions before 2.11.35; 3.0.0 to before 3.6.7 Vulnerable ·traefik

Remediation

Fix · CNA traefik (traefik) Fixed in 2.11.35, 3.6.7
Fix · GHSA-cwjm-3f7h-9hwq github.com/traefik/traefik/v3 (Go) Fixed in 3.6.7 Advisory →
Fix · GHSA-cwjm-3f7h-9hwq github.com/traefik/traefik/v2 (Go) Fixed in 2.11.35 Advisory →

Red Hat 1 advisory

RHSA-2026:6192 Released 2026-03-30 · Red Hat rating Important
Red Hat OpenShift Dev Spaces 3.27.0 Release.
- Red Hat OpenShift Dev Spaces 3.27 registry.redhat.io/devspaces/code-rhel9, registry.redhat.io/devspaces/configbump-rhel9, registry.redhat.io/devspaces/dashboard-rhel9 +9

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

Product	Status	Plan or fix
Red Hat OpenShift Dev Spaces 3.27	Fixed	RHSA-2026:6192

Not affected: 1 product

Red Hat OpenShift Dev Spaces 3.27

Timeline

2026-10-02 Threatist record created from CVE-2026-22045
2026-10-03 Alias added: GHSA-cwjm-3f7h-9hwq

References

Patch 2

Advisory 1

https://nvd.nist.gov/vuln/detail/CVE-2026-22045

Other 3

TI-2023-23979 The HTTP/2 protocol allows a denial of service (server resource consumption) because… KEVCVSS 3.1HIGH 7.5
TI-2023-25774 Uncontrolled Resource Consumption in Traefik CVSS 3.1HIGH 7.5
TI-2025-40914 Traefik doesn't Prevent Path Normalization Bypass in Router + Middleware Rules CVSS 4.0MEDIUM 6.9
TI-2022-07529 Authorization header displayed in the debug logs CVSS 3.1MEDIUM 6.5
TI-2024-30459 HTTP client can remove the X-Forwarded headers in Traefik CVSS 3.1CRITICAL 9.8
TI-2026-60261 Traefik v3.7.0 Authentication Bypass via from-to-www-redirect CVSS 4.0CRITICAL 9.3

See all 83 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences