Caddy is an extensible server platform that uses TLS by default. From 2.4.0 until 2.11.3, the authorization layer and the /config traversal layer do not agree on what object the path refers to. In this case, a path authorized for one config object is accepted, but then resolves to a different config object during traversal. This happens because the authorization layer uses string prefix matching and the /config traversal layer parses array indices numerically using strconv.Atoi(). This vulnerability is fixed in 2.11.3.

The remote Debian 13 host has a package installed that is affected by multiple vulnerabilities as referenced in the dsa-6429 advisory.

    - -------------------------------------------------------------------------     Debian Security Advisory DSA-6429-1                   security@debian.org     https://www.debian.org/security/                                  Aron Xu     August 11, 2026                       https://www.debian.org/security/faq
    - -------------------------------------------------------------------------

    Package        : caddy     CVE ID         : CVE-2026-27585 CVE-2026-27587 CVE-2026-27588 CVE-2026-27589                      CVE-2026-27590 CVE-2026-45692 CVE-2026-52845 CVE-2026-52846

    Multiple security issues were discovered in Caddy, a web server with     automatic HTTPS, which may result in the bypass of path- or host-based     access controls, the execution of an unintended file by a FastCGI     backend, the injection of identity headers trusted by applications     running behind Caddy, unauthorised reconfiguration of the server through     its admin API, or cross-site scripting.

    The fix for CVE-2026-52845 follows upstream in dropping every request     header whose name contains an underscore, for all servers and without an     opt-out. Deployments which pass such headers through Caddy, for instance     X_Api_Key or gRPC custom metadata keys containing underscores, need to     switch to the hyphenated spelling.

    For the stable distribution (trixie), these problems have been fixed in     version 2.6.2-12+deb13u1.

    We recommend that you upgrade your caddy packages.

    For the detailed security status of caddy please refer to     its security tracker page at:
    https://security-tracker.debian.org/tracker/caddy

    Further information about Debian Security Advisories, how to apply     these updates to your system and frequently asked questions can be     found at: https://www.debian.org/security/

    Mailing list: debian-security-announce@lists.debian.org

Tenable has extracted the preceding description block directly from the Debian security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - Caddy is an extensible server platform that uses TLS by default. From 2.4.0 until 2.11.3, the     authorization layer and the /config traversal layer do not agree on what object the path refers to. In     this case, a path authorized for one config object is accepted, but then resolves to a different config     object during traversal. This happens because the authorization layer uses string prefix matching and the     /config traversal layer parses array indices numerically using strconv.Atoi(). This vulnerability is fixed     in 2.11.3. (CVE-2026-45692)

Note that Nessus relies on the presence of the package as reported by the vendor.

There are packages installed that are affected by multiple vulnerabilities referenced in the following CVEs:

  - Caddy is an extensible server platform that uses TLS by default. From 2.7.0 until 2.11.3, the FastCGI
    transport's splitPos() in modules/caddyhttp/reverseproxy/fastcgi/fastcgi.go misuses
    golang.org/x/text/search with search.IgnoreCase when the request path contains a non-ASCII byte. Two
    distinct flaws in that fallback let an attacker mislead Caddy's FastCGI splitting into treating a non-.php
    (or other configured split_path extension) file as a script. In any deployment where the attacker can
    place content into a file served via FastCGI (uploads, file storage, etc.), this can be escalated to
    remote code execution by crafting a URL whose path triggers either flaw. This vulnerability is fixed in
    2.11.3. (CVE-2026-45135)

  - Caddy is an extensible server platform that uses TLS by default. From 2.4.0 until 2.11.3, the
    authorization layer and the /config traversal layer do not agree on what object the path refers to. In
    this case, a path authorized for one config object is accepted, but then resolves to a different config
    object during traversal. This happens because the authorization layer uses string prefix matching and the
    /config traversal layer parses array indices numerically using strconv.Atoi(). This vulnerability is fixed
    in 2.11.3. (CVE-2026-45692)

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - Caddy is an extensible server platform that uses TLS by default. From 2.4.0 until 2.11.3, the
    authorization layer and the /config traversal layer do not agree on what object the path refers to. In
    this case, a path authorized for one config object is accepted, but then resolves to a different config
    object during traversal. This happens because the authorization layer uses string prefix matching and the
    /config traversal layer parses array indices numerically using strconv.Atoi(). This vulnerability is fixed
    in 2.11.3. (CVE-2026-45692)

ID	Name	Product	Family	Type	Severity
334443	Debian dsa-6429 : caddy - security update	Nessus	Debian Local Security Checks	Local	critical
322473	Linux Distros Unpatched Vulnerability : CVE-2026-45692	Nessus	Misc.	Local	low
443105	Alpine: multiple caddy packages: security update to 2.11.4-r0	Tenable Cloud Security	Alpine Linux Local Security Checks	Local	low
443105	Alpine: multiple caddy packages: security update to 2.11.4-r0	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	Local	low
442157	SCA: security update for github.com/caddyserver/caddy/v2 (GHSA-x5w9-xh9r-mvfc)	Tenable Cloud Security	SCA Checks	Local	low
442157	SCA: security update for github.com/caddyserver/caddy/v2 (GHSA-x5w9-xh9r-mvfc)	Tenable Self-Hosted Container Security	SCA Checks	Local	low

Detections

Analytics

CVE-2026-45692

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Tenable Plugins

critical

low

low

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low

low