Underscore.js is a utility-belt library for JavaScript. Prior to 1.13.8, the _.flatten and _.isEqual functions use recursion without a depth limit. Under very specific conditions, detailed below, an attacker could exploit this in a Denial of Service (DoS) attack by triggering a stack overflow. Untrusted input must be used to create a recursive datastructure, for example using JSON.parse, with no enforced depth limit. The datastructure thus created must be passed to _.flatten or _.isEqual. In the case of _.flatten, the vulnerability can only be exploited if it is possible for a remote client to prepare a datastructure that consists of arrays at all levels AND if no finite depth limit is passed as the second argument to _.flatten. In the case of _.isEqual, the vulnerability can only be exploited if there exists a code path in which two distinct datastructures that were submitted by the same remote client are compared using _.isEqual. For example, if a client submits data that are stored in a database, and the same client can later submit another datastructure that is then compared to the data that were saved in the database previously, OR if a client submits a single request, but its data are parsed twice, creating two non-identical but equivalent datastructures that are then compared. Exceptions originating from the call to _.flatten or _.isEqual, as a result of a stack overflow, are not being caught. This vulnerability is fixed in 1.13.8.

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

  - Underscore.js is a utility-belt library for JavaScript. Prior to 1.13.8, the _.flatten and _.isEqual     functions use recursion without a depth limit. Under very specific conditions, detailed below, an attacker     could exploit this in a Denial of Service (DoS) attack by triggering a stack overflow. Untrusted input     must be used to create a recursive datastructure, for example using JSON.parse, with no enforced depth     limit. The datastructure thus created must be passed to _.flatten or _.isEqual. In the case of _.flatten,     the vulnerability can only be exploited if it is possible for a remote client to prepare a datastructure     that consists of arrays at all levels AND if no finite depth limit is passed as the second argument to
    _.flatten. In the case of _.isEqual, the vulnerability can only be exploited if there exists a code path     in which two distinct datastructures that were submitted by the same remote client are compared using
    _.isEqual. For example, if a client submits data that are stored in a database, and the same client can     later submit another datastructure that is then compared to the data that were saved in the database     previously, OR if a client submits a single request, but its data are parsed twice, creating two non-     identical but equivalent datastructures that are then compared. Exceptions originating from the call to
    _.flatten or _.isEqual, as a result of a stack overflow, are not being caught. This vulnerability is fixed     in 1.13.8. (CVE-2026-27601)

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

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

  - Underscore.js is a utility-belt library for JavaScript. Prior to 1.13.8, the _.flatten and _.isEqual
    functions use recursion without a depth limit. Under very specific conditions, detailed below, an attacker
    could exploit this in a Denial of Service (DoS) attack by triggering a stack overflow. Untrusted input
    must be used to create a recursive datastructure, for example using JSON.parse, with no enforced depth
    limit. The datastructure thus created must be passed to _.flatten or _.isEqual. In the case of _.flatten,
    the vulnerability can only be exploited if it is possible for a remote client to prepare a datastructure
    that consists of arrays at all levels AND if no finite depth limit is passed as the second argument to
    _.flatten. In the case of _.isEqual, the vulnerability can only be exploited if there exists a code path
    in which two distinct datastructures that were submitted by the same remote client are compared using
    _.isEqual. For example, if a client submits data that are stored in a database, and the same client can
    later submit another datastructure that is then compared to the data that were saved in the database
    previously, OR if a client submits a single request, but its data are parsed twice, creating two non-
    identical but equivalent datastructures that are then compared. Exceptions originating from the call to
    _.flatten or _.isEqual, as a result of a stack overflow, are not being caught. This vulnerability is fixed
    in 1.13.8. (CVE-2026-27601)

ID	Name	Product	Family	Severity
300943	Linux Distros Unpatched Vulnerability : CVE-2026-27601	Nessus	Misc.	high
438099	SCA: security update for underscore (GHSA-qpx9-hpmf-5gmw)	Tenable Cloud Security	SCA Checks	high
438099	SCA: security update for underscore (GHSA-qpx9-hpmf-5gmw)	Tenable Self-Hosted Container Security	SCA Checks	high

Detections

Analytics

CVE-2026-27601

high

Tenable Plugins

high

high

high