CVE-2026-45692: Caddyserver Caddy authorization bypass in /config API via array index normalization

CVE-2026-45692 · Severity: medium · CVSS 5.4 · Published 2026-06-23

Caddy is a web server platform used to host websites and manage network traffic. A security flaw in its remote administration interface allows an authorized user with restricted access to bypass those restrictions and modify or view configuration settings they should not be able to reach. This could allow a low-privileged administrator to change how the server handles traffic or access sensitive internal configuration data.

Technologies: github.com/caddyserver/caddy/v2 (Go). Vendors: Go.

Quick answers

Is CVE-2026-45692 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-45692 being exploited in the wild.
How severe is CVE-2026-45692?
Medium severity, with a CVSS score of 5.4, published 23 June 2026.
Which products and versions are affected?
github.com/caddyserver/caddy/v2 (Go) >= 2.4.0, < 2.11.3, SEMVER:introduced=2.4.0,fixed=2.11.3.
Is there a fix for CVE-2026-45692?
Yes. github.com/caddyserver/caddy/v2 (Go): upgrade to 2.11.3 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-45692 attacked?
It is attacked over the network, in a hosted service.
Am I affected by CVE-2026-45692?
Check whether you run github.com/caddyserver/caddy/v2 (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • github.com/caddyserver/caddy/v2 (Go): upgrade to 2.11.3 or later
    go get github.com/caddyserver/caddy/v2@v2.11.3

Technical details

An authorization bypass exists in Caddy's remote admin API due to an inconsistency between path-based authorization and configuration traversal. The authorization layer uses string prefix matching (e.g., allowing access to '/config/.../routes/0'), while the traversal layer parses array indices numerically using 'strconv.Atoi()'. An attacker with a restricted admin certificate can use leading zeros (e.g., requesting '/config/.../routes/01') to satisfy the prefix match for index '0' while the traversal layer resolves the path to index '1'. This allows an authenticated remote administrator to read or modify configuration objects outside of their assigned scope. The issue is fixed in version 2.11.3.

Affected products

  • Caddyserver Caddy >= 2.4.0, < 2.11.3

Identifiers

  • CVE-2026-45692
  • GHSA-x5w9-xh9r-mvfc
  • GO-2026-5743

Timeline

  • 2026-05-13: advisory: GitHub Security Advisory published by maintainers
  • 2026-06-23: disclosed: CVE published to NVD
  • 2026-06-23: patched: Fix released in version 2.11.3

References

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