JasonLovesDoggo Defender Plugin up to 0.10.0 Trusted Proxy locking

Summaryinfo

A vulnerability classified as very critical was found in JasonLovesDoggo Defender Plugin up to 0.10.0. Affected is an unknown function of the component Trusted Proxy. Executing a manipulation can lead to locking. This vulnerability is tracked as CVE-2026-46415. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability has been found in JasonLovesDoggo Defender Plugin up to 0.10.0 and classified as very critical. This vulnerability affects an unknown function of the component Trusted Proxy. The manipulation with an unknown input leads to a locking vulnerability. The CWE definition for the vulnerability is CWE-667. The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

The Caddy Defender plugin is a middleware for Caddy that allows users to block or manipulate requests based on the client's IP address. Prior to version 0.10.1, Caddy Defender used `r.RemoteAddr` when evaluating whether a request should be blocked. `RemoteAddr` is the address of the immediate peer connected to Caddy. In deployments where Caddy is behind a trusted proxy, CDN, or load balancer, the immediate peer is usually the proxy, not the original client. Caddy resolves the original client address into its `client_ip` request variable after applying the configured `trusted_proxies` policy, but Defender did not use that value. As a result, clients from blocked IP ranges could bypass Defender when accessing Caddy through a trusted proxy whose own IP address was not blocked. This affects deployments that use Defender behind trusted proxies and expect it to enforce blocking based on the real client IP. The issue is fixed in version 0.10.1 by making Defender prefer Caddys resolved `client_ip` request variable when it is available. Defender falls back to `RemoteAddr` only when Caddy has not provided a resolved client IP. There is no complete workaround in affected Defender versions for deployments that rely on Caddy's trusted proxy client IP resolution. Until upgrading, affected users should enforce equivalent IP blocking at the trusted proxy, CDN, load balancer, firewall, or other edge layer before traffic reaches Caddy. Deployments where Caddy receives traffic directly from clients, without an intermediate trusted proxy, are not affected by this bypass.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-46415 since 05/13/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 07/20/2026).

Upgrading to version 0.10.1 eliminates this vulnerability.

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Productinfo

Vendor

• JasonLovesDoggo

Name

• Defender Plugin

Version

• 0.1
• 0.2
• 0.3
• 0.4
• 0.5
• 0.6
• 0.7
• 0.8
• 0.9
• 0.10.0

CPE 2.3info

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CPE 2.2info

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