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CVE-2015-8861 Handlebars.js Project CVE debrief

CVE-2015-8861 describes a cross-site scripting flaw in handlebars.js for Node.js versions before 4.0.0. According to NVD, the issue can be triggered through a template that uses an attribute without quotes, which can lead to client-side script execution in affected web applications.

Vendor
Handlebars.js Project
Product
CVE-2015-8861
CVSS
MEDIUM 6.1
CISA KEV
Not listed in stored evidence
Original CVE published
2017-01-23
Original CVE updated
2026-05-13
Advisory published
2017-01-23
Advisory updated
2026-05-13

Who should care

Teams that build or maintain Node.js applications using handlebars.js before 4.0.0, especially applications that render HTML templates and may output user-influenced content.

Technical summary

NVD classifies the weakness as CWE-79 and assigns CVSS 3.1 vector CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N (6.1, Medium). The affected version range is limited to handlebars.js versions earlier than 4.0.0. The vulnerability is tied to templates that contain an unquoted attribute, which can enable XSS when rendered in a browser.

Defensive priority

Medium. The issue requires user interaction but can affect browser-exposed applications that render HTML from affected templates, so upgrading and template review are worthwhile if handlebars.js is in use.

Recommended defensive actions

  • Upgrade handlebars.js to version 4.0.0 or later.
  • Audit templates for unquoted HTML attributes and correct them to quoted form.
  • Review any template paths that render untrusted or user-influenced data.
  • Validate rendered output with security-focused testing or code review.
  • Check the NVD record and linked advisories for any product-specific guidance.

Evidence notes

The vulnerability description, version boundary, and CWE come from NVD. The CVSS vector and score are taken from the supplied NVD data. The linked references include a mailing-list disclosure, third-party advisories, and a sourceclear write-up; no exploit code or weaponized reproduction is included here.

Official resources

Published by NVD on 2017-01-23T21:59:00.720Z; later modified on 2026-05-13T00:24:29.033Z. The linked references include 2016 disclosures and advisories, but those are supporting references rather than the CVE publication date.