Resource exhaustion in Jashkenas Underscore
CVE-2026-27601
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…
EPSS: 0.006 (44.8th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Jashkenas Underscore — versions < 1.13.8
- Underscorejs Underscore
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Patch, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Patch, x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-27601?
- CVE-2026-27601 is a medium-severity vulnerability in Jashkenas Underscore, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 5.9/10. Published 2026-03-03.
- How severe is CVE-2026-27601?
- Medium severity. CVSS v3 base score is 5.9 out of 10.