CVE-2026-27601
Description
A flaw was found in Underscore.js, a JavaScript utility library. This vulnerability allows a remote attacker to trigger a Denial of Service (DoS) attack by providing specially crafted recursive data structures. When these structures are processed by the _.flatten or _.isEqual functions, which lack a depth limit for recursion, a stack overflow occurs. This can make the application unavailable to legitimate users.
Mitigation
To mitigate this issue, applications utilizing Underscore.js should ensure that any processing of untrusted, recursively structured data with `_.flatten` or `_.isEqual` explicitly enforces a finite depth limit. Review application code to identify and modify calls to these functions, adding appropriate depth parameters to prevent stack overflow conditions. Additionally, input validation should be implemented to sanitize untrusted data before it is processed by Underscore.js functions.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.9 | 5.9 | N/A |
| Attack Vector | Network | Network | N/A |
| Attack Complexity | High | High | N/A |
| Privileges Required | None | None | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (CPU)
Frequently Asked Questions
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