Traefik up to 3.6.9 Query Parameter injection

Summaryinfo

A vulnerability, which was classified as problematic, has been found in Traefik up to 3.6.9. This affects an unknown function of the component Query Parameter Handler. The manipulation leads to injection. This vulnerability is referenced as CVE-2026-29777. Remote exploitation of the attack is possible. No exploit is available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in Traefik up to 3.6.9. This issue affects an unknown functionality of the component Query Parameter Handler. The manipulation with an unknown input leads to a injection vulnerability. Using CWE to declare the problem leads to CWE-74. The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

Traefik is an HTTP reverse proxy and load balancer. Prior to 3.6.10, A tenant with write access to an HTTPRoute resource can inject backtick-delimited rule tokens into Traefik's router rule language via unsanitized header or query parameter match values. In shared gateway deployments, this can bypass listener hostname constraints and redirect traffic for victim hostnames to attacker-controlled backends. This vulnerability is fixed in 3.6.10.

It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-29777 since 03/04/2026. The exploitation is known to be easy. The attack may be initiated remotely. The exploitation requires an enhanced level of successful authentication. The technical details are unknown and an exploit is not publicly available. The attack technique deployed by this issue is T1055 according to MITRE ATT&CK.

The vulnerability scanner Nessus provides a plugin with the ID 318669 (Traefik < 3.6.10 HTTPRoute Rule Injection), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 3.6.10 eliminates this vulnerability. The upgrade is hosted for download at github.com.

The vulnerability is also documented in the vulnerability database at Tenable (318669). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Name

• Traefik

Version

• 3.6.0
• 3.6.1
• 3.6.2
• 3.6.3
• 3.6.4
• 3.6.5
• 3.6.6
• 3.6.7
• 3.6.8
• 3.6.9

Website

• Product: https://github.com/traefik/traefik/

CPE 2.3info

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CPE 2.2info

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Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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