Echo is a Go web framework. Prior to 4.15.3 and 5.2.0, Echo's router and static file handler disagree on URL path decoding. The router matches routes using the raw encoded path (preserving %2F as-is), while StaticDirectoryHandler unescapes %2F to / before resolving filesystem paths. This allows an attacker to bypass route-level access controls and read static files without authorization. This vulnerability is fixed in 4.15.3 and 5.2.0.

The remote Redhat Enterprise Linux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2026:61585 advisory.

    A service for building customized OS artifacts, such as VM images and OSTree commits, that uses osbuild     under the hood. Besides building images for local usage, it can also upload images directly to cloud.  It     is compatible with composer-cli and cockpit-composer clients.

    Security Fix(es):

    * golang.org/x/net/html: golang: golang.org/x/net/html: Cross-Site Scripting via HTML parsing bypass     (CVE-2026-27136)

    * golang.org/x/net/html: golang.org/x/net/html: Arbitrary code execution via Cross-Site Scripting     (CVE-2026-25681)

    * golang.org/x/net/html: golang: golang.org/x/net/html: Cross-Site Scripting via unexpected HTML tree     rendering (CVE-2026-42502)

    * github.com/labstack/echo: Echo: Unauthorized Information Disclosure via URL Path Decoding Discrepancy     (CVE-2026-55677)

    For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and     other related information, refer to the CVE page(s) listed in the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

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

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

  - Echo is a Go web framework. Prior to 4.15.3 and 5.2.0, Echo's router and static file handler disagree on
    URL path decoding. The router matches routes using the raw encoded path (preserving %2F as-is), while
    StaticDirectoryHandler unescapes %2F to / before resolving filesystem paths. This allows an attacker to
    bypass route-level access controls and read static files without authorization. This vulnerability is
    fixed in 4.15.3 and 5.2.0. (CVE-2026-55677)

The remote Redhat Enterprise Linux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2026:57541 advisory.

    A service for building customized OS artifacts, such as VM images and OSTree commits, that uses osbuild     under the hood. Besides building images for local usage, it can also upload images directly to cloud.  It     is compatible with composer-cli and cockpit-composer clients.

    Security Fix(es):

    * golang.org/x/net/idna: golang: net/http: golang.org/x/net/idna: Privilege escalation via incorrect     Punycode label processing (CVE-2026-39821)

    * github.com/labstack/echo: Echo: Unauthorized Information Disclosure via URL Path Decoding Discrepancy     (CVE-2026-55677)

    For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and     other related information, refer to the CVE page(s) listed in the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux 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.

  - Echo is a Go web framework. Prior to 4.15.3 and 5.2.0, Echo's router and static file handler disagree on     URL path decoding. The router matches routes using the raw encoded path (preserving %2F as-is), while     StaticDirectoryHandler unescapes %2F to / before resolving filesystem paths. This allows an attacker to     bypass route-level access controls and read static files without authorization. This vulnerability is     fixed in 4.15.3 and 5.2.0. (CVE-2026-55677)

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

ID	Name	Product	Family	Type	Severity
342031	RHEL 9 : osbuild-composer (RHSA-2026:61585)	Nessus	Red Hat Local Security Checks	Local	high
446272	SCA: security update for github.com/labstack/echo/v4, github.com/labstack/echo/v5 (GHSA-vfp3-v2gw-7wfq)	Tenable Cloud Security	SCA Checks	Local	high
446272	SCA: security update for github.com/labstack/echo/v4, github.com/labstack/echo/v5 (GHSA-vfp3-v2gw-7wfq)	Tenable Self-Hosted Container Security	SCA Checks	Local	high
338333	RHEL 9 : osbuild-composer (RHSA-2026:57541)	Nessus	Red Hat Local Security Checks	Local	high
323662	Linux Distros Unpatched Vulnerability : CVE-2026-55677	Nessus	Misc.	Local	high

Detections

Analytics

CVE-2026-55677

high

Tenable Plugins

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high

high

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high