Traefik
CVE-2026-26999
HIGH
GHSA-xw98-5q62-jx94
Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Primary rating from Vendor (github).
CVSS VectorVendor: github
Lifecycle Timeline
3DescriptionCVE.org
Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.38 and 3.6.9, there is a potential vulnerability in Traefik managing TLS handshake on TCP routers. When Traefik processes a TLS connection on a TCP router, the read deadline used to bound protocol sniffing is cleared before the TLS handshake is completed. When a TLS handshake read error occurs, the code attempts a second handshake with different connection parameters, silently ignoring the initial error. A remote unauthenticated client can exploit this by sending an incomplete TLS record and stopping further data transmission, causing the TLS handshake to stall indefinitely and holding connections open. By opening many such stalled connections in parallel, an attacker can exhaust file descriptors and goroutines, degrading availability of all services on the affected entrypoint. This issue has been patched in versions 2.11.38 and 3.6.9.
AnalysisAI
Traefik versions before 2.11.38 and 3.6.9 allow remote attackers to cause denial of service by sending incomplete TLS records to TCP routers, which causes the TLS handshake process to hang indefinitely while holding connections open. An unauthenticated attacker can exploit this by opening many stalled connections in parallel to exhaust file descriptors and goroutines, degrading or disabling the proxy service.
Technical ContextAI
Classified as CWE-400 (Uncontrolled Resource Consumption). Affects Traefik. Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.38 and 3.6.9, there is a potential vulnerability in Traefik managing TLS handshake on TCP routers. When Traefik processes a TLS connection on a TCP router, the read deadline used to bound protocol sniffing is cleared before the TLS handshake is completed. When a TLS handshake read error occurs, the code attempts a second handshake with different connection parameters, silently ignoring the initial error. A remote unauthen
RemediationAI
A vendor patch is available — apply it immediately. Restrict network access to the affected service where possible.
Denial of service against HTTP/2 server implementations allows remote unauthenticated attackers to exhaust server resour
Traefik is an open source HTTP reverse proxy and load balancer. Rated high severity (CVSS 7.5), this vulnerability is re
types/types.go in Containous Traefik 1.7.x through 1.7.11, when the --api flag is used and the API is publicly reachable
Traefik is an open source HTTP reverse proxy and load balancer. Rated medium severity (CVSS 6.5), this vulnerability is
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Authorization bypass in Traefik's IngressRouteTCP handler (versions 3.6.0-3.6.22 and 3.7.0-3.7.6) allows a low-privilege
Traefik (pronounced traffic) is an HTTP reverse proxy and load balancer. Rated high severity (CVSS 8.8), this vulnerabil
Traefik before 2.10.5 and 3.0.0-beta4 is affected by a denial-of-service vulnerability in HTTP/2 request handling inheri
In Traefik before versions 1.7.26, 2.2.8, and 2.3.0-rc3, there exists a potential open redirect vulnerability in Traefik
Client-certificate authentication (mTLS) in Traefik before v2.11.55 can be silently bypassed by unauthenticated network
Same weakness CWE-400 – Uncontrolled Resource Consumption
View allSame technique Denial Of Service
View allVendor StatusVendor
SUSE
Severity: High| Product | Status |
|---|---|
| openSUSE Tumbleweed | Fixed |
| openSUSE Leap 15.6 | Fixed |
| SUSE Linux Enterprise Module for Package Hub 15 SP5 | Fixed |
| SUSE Linux Enterprise Module for Package Hub 15 SP6 | Fixed |
| openSUSE Leap 15.5 | Fixed |
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External POC / Exploit Code
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