SB2026111224 - Server-Side Request Forgery (SSRF) in Happy DOM

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Main Vulnerability Database SB2026111224

SB2026111224 - Server-Side Request Forgery (SSRF) in Happy DOM

Published: November 12, 2026

Security Bulletin ID SB2026111224
CSH Severity
High
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Information disclosure

Breakdown by Severity

High 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Server-Side Request Forgery (SSRF) (CVE-ID: CVE-2026-118660)

CWE-ID: CWE-918 - Server-Side Request Forgery (SSRF)

CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:L/SI:N/SA:N]


The vulnerability allows a remote attacker to disclose cloud credentials and sensitive internal data through server-side request forgery.

The vulnerability exists due to unrestricted server-side resource loading in Happy DOM's HTML parser when processing untrusted HTML with default settings. A remote attacker can supply HTML containing <iframe src="http://169.254.169.254/latest/meta-data/iam/security-credentials/"></iframe> or <link rel="stylesheet" href="http://127.0.0.1:9995/stylesheet-ssrf"> to trigger requests to internal services or cloud metadata endpoints and disclose sensitive responses.


Remediation

Install update from vendor's website.

References