CVE-2022-23632

Traefik skips the router TLS configuration when the host header is an FQDN

HIGH
7.5
CVSS Score
Published: February 17, 2022 at 02:55 PM UTC
Updated: June 17, 2026 at 04:30 AM UTC
2 products affected across 2 vendorsTraefikCommunications Unified Inventory Management

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Severity
HIGH7.5
Exploit prediction
EPSS 2%
SSVC
No known exploit

Description

Traefik is an HTTP reverse proxy and load balancer. Prior to version 2.6.1, Traefik skips the router transport layer security (TLS) configuration when the host header is a fully qualified domain name (FQDN). For a request, the TLS configuration choice can be different than the router choice, which implies the use of a wrong TLS configuration. When sending a request using FQDN handled by a router configured with a dedicated TLS configuration, the TLS configuration falls back to the default configuration that might not correspond to the configured one. If the CNAME flattening is enabled, the selected TLS configuration is the SNI one and the routing uses the CNAME value, so this can skip the expected TLS configuration. Version 2.6.1 contains a patch for this issue. As a workaround, one may add the FDQN to the host rule. However, there is no workaround if the CNAME flattening is enabled.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 2.6.1
Affected range stops below 2.6.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (4)

x_refsource_MISCIssue TrackingPatchThird Party Advisory
https://github.com/traefik/traefik/pull/8764
x_refsource_MISCRelease NotesThird Party Advisory
https://github.com/traefik/traefik/releases/tag/v2.6.1

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-295

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