Handlebars provides the power necessary to let users build semantic templates. In versions 4.0.0 through 4.7.8, when a Handlebars template contains decorator syntax referencing an unregistered decorator (e.g. `{{*n}}`), the compiled template calls `lookupProperty(decorators, "n")`, which returns `undefined`. The runtime then immediately invokes the result as a function, causing an unhandled `TypeError: ... is not a function` that crashes the Node.js process. Any application that compiles user-supplied templates without wrapping the call in a `try/catch` is vulnerable to a single-request Denial of Service. Version 4.7.9 fixes the issue. Some workarounds are available. Wrap compilation and rendering in `try/catch`. Validate template input before passing it to `compile()`; reject templates containing decorator syntax (`{{*...}}`) if decorators are not used in your application. Use the pre-compilation workflow; compile templates at build time and serve only pre-compiled templates; do not call `compile()` at request time.

The remote Fedora 44 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-cb5661d883 advisory.

    33.0.3 Release

Tenable has extracted the preceding description block directly from the Fedora 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 remote Fedora 42 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-2fed8dd674 advisory.

    33.0.3 Release

Tenable has extracted the preceding description block directly from the Fedora 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.

  - Handlebars provides the power necessary to let users build semantic templates. In versions 4.0.0 through     4.7.8, when a Handlebars template contains decorator syntax referencing an unregistered decorator (e.g.
    `{{*n}}`), the compiled template calls `lookupProperty(decorators, n)`, which returns `undefined`. The     runtime then immediately invokes the result as a function, causing an unhandled `TypeError: ... is not a     function` that crashes the Node.js process. Any application that compiles user-supplied templates without     wrapping the call in a `try/catch` is vulnerable to a single-request Denial of Service. Version 4.7.9     fixes the issue. Some workarounds are available. Wrap compilation and rendering in `try/catch`. Validate     template input before passing it to `compile()`; reject templates containing decorator syntax (`{{*...}}`)     if decorators are not used in your application. Use the pre-compilation workflow; compile templates at     build time and serve only pre-compiled templates; do not call `compile()` at request time.
    (CVE-2026-33939)

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

ID	Name	Product	Family	Severity
313662	Fedora 44 : nextcloud (2026-cb5661d883)	Nessus	Fedora Local Security Checks	medium
313661	Fedora 42 : nextcloud (2026-2fed8dd674)	Nessus	Fedora Local Security Checks	medium
304155	Linux Distros Unpatched Vulnerability : CVE-2026-33939	Nessus	Misc.	high

Detections

Analytics

CVE-2026-33939

high

Tenable Plugins

medium

medium

high