CVE-2026-46415: Pkg.jsn.cam/caddy defender Caddy Defender Trusted Proxy Client Vulnerability

HIGH
Advisory Identifier: GHSA-3h23-rrpc-3p87
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CVSS 8.2
CWE-284 CWE-348
Published
Advisory Summary

CVE-2026-46415 is a HIGH (CVSS 8.2) caddy defender trusted proxy client vulnerability (CWE-284: Improper Access Control) affecting Pkg.jsn.cam/caddy defender libraries in the Go ecosystem. The issue involves caddy defender trusted proxy client ip bypass. Remediation is available by upgrading affected packages to version 0.10.1.

CVE-2026-46415 at a Glance

CVE Identifier CVE-2026-46415
GHSA Identifier GHSA-3h23-rrpc-3p87
Severity HIGH
CVSS v3.1 Base Score 8.2
CWE Classification CWE-284: Improper Access Control
Affected Product Pkg.jsn.cam/caddy defender
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 8.2

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity Low (I:L)
Availability None (A:N)

How to Fix CVE-2026-46415

To remediate this vulnerability, upgrade all affected Pkg.jsn.cam/caddy defender dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

pkg.jsn.cam/caddy-defender fixed: 0.10.1 
Upgrade pkg.jsn.cam/caddy-defender to 0.10.1
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for pkg.jsn.cam/caddy-defender

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-46415, inspect your project dependencies for Pkg.jsn.cam/caddy defender:

inspect dependencies for pkg.jsn.cam/caddy-defender

Analyze the terminal output to locate any version of Pkg.jsn.cam/caddy defender in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.10.1), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-284: Improper Access Control, where the product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. In Pkg.jsn.cam/caddy defender, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Impact 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. ### Patches The issue is fixed 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. Users should upgrade to `v0.10.1` or later. ### Workarounds There is no complete workaround in affected Defender versions for deployments that rely on Caddys 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.

CVE-2026-46415 Affected Pkg.jsn.cam/caddy defender Versions

1 component(s)
Fixed Versions:
0.10.1
Product / Package Ecosystem Affected Versions Fixed Version
pkg.jsn.cam/caddy-defender
golang/pkg.jsn.cam/caddy-defender
Go
< 0.10.1
0.10.1

References

GitHub Advisory / Wiki ADVISORY
https://github.com/JasonLovesDoggo/caddy-defender/security/advisories/GHSA-3h23-rrpc-3p87
Pkg.jsn.cam/caddy defender Source Repository REPOSITORY
https://github.com/JasonLovesDoggo/caddy-defender/pull/139
Pkg.jsn.cam/caddy defender Source Repository REPOSITORY
https://github.com/JasonLovesDoggo/caddy-defender

Frequently Asked Questions

What is CVE-2026-46415?
CVE-2026-46415 is a security vulnerability in Pkg.jsn.cam/caddy defender involving Caddy Defender trusted proxy client IP bypass under CWE-284: Improper Access Control.
Which Pkg.jsn.cam/caddy defender versions are affected?
Affected versions include releases prior to 0.10.1 across affected packages: pkg.jsn.cam/caddy-defender.
What version fixes CVE-2026-46415?
Upgrading to 0.10.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is pkg.jsn.cam/caddy-defender affected?
Yes, pkg.jsn.cam/caddy-defender is affected in releases prior to 0.10.1. Upgrade your dependency to 0.10.1 or later.
What is the CVSS score of CVE-2026-46415?
CVE-2026-46415 has a CVSS v3.1 base score of 8.2 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N.
What CWE is associated with CVE-2026-46415?
CVE-2026-46415 is classified under CWE-284: Improper Access Control (The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.).
How can I check Go dependencies for CVE-2026-46415?
Run the dependency tree command: 'inspect dependencies for pkg.jsn.cam/caddy-defender'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-3h23-rrpc-3p87",
  "modified" : "2026-05-19T20:29:14Z",
  "published" : "2026-05-19T20:29:14Z",
  "aliases" : [ "CVE-2026-46415" ],
  "summary" : "Caddy Defender trusted proxy client IP bypass",
  "details" : "### Impact\n\nCaddy Defender used `r.RemoteAddr` when evaluating whether a request should be blocked. `RemoteAddr` is the address of the immediate peer connected to Caddy.\n\nIn 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.\n\nAs 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.\n\n### Patches\n\nThe issue is fixed 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.\n\nUsers should upgrade to `v0.10.1` or later.\n\n### Workarounds\n\nThere is no complete workaround in affected Defender versions for deployments that rely on Caddys trusted proxy client IP resolution.\n\nUntil upgrading, affected users should enforce equivalent IP blocking at the trusted proxy, CDN, load balancer, firewall, or other edge layer before traffic reaches Caddy.\n\nDeployments where Caddy receives traffic directly from clients, without an intermediate trusted proxy, are not affected by this bypass.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "pkg.jsn.cam/caddy-defender"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.10.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/JasonLovesDoggo/caddy-defender/security/advisories/GHSA-3h23-rrpc-3p87"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/JasonLovesDoggo/caddy-defender/pull/139"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/JasonLovesDoggo/caddy-defender"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-284", "CWE-348" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-05-19T20:29:14Z",
    "nvd_published_at" : null
  }
}