Happy DOM: SSRF via iframe and link stylesheet when parsing untrusted HTML
CVSS score
8.6
EPSS probability
—
Risk score
0.9
Published
2 h ago
Resmî kaynaklarda yeterli kanıt bulunamadı. Bu sonuç “yama yok” anlamına gelmez.
Impact on My Inventory
Only the personal products you have added to your account are assessed; an organisation's inventory does not appear here.
Checking session…
Vulnerability description
DayBreach AI Explanation
Verified against sourcesSources read
1
Source agreement
Tam uyum
Evidence confidence
%55
Short explanation
When parsing untrusted HTML, Happy DOM loads iframe and link rel="stylesheet" URLs by default [S0]. This allows attackers to trigger server-side requests to arbitrary internal or cloud endpoints and expose confidential responses [S0].
Applications processing untrusted content without explicit opt-in configurations can become vulnerable to server-side request forgery risks [S0].
What should be done?
- Update to version 21.0.0 or later [S0]
- Follow the vendor advisory [S0]
Chain of evidence and sources
Happy DOM, 21.0.0 öncesi sürümlerde disableIframePageLoading ve disableCSSFileLoading varsayılan olarak false olduğu için iframe ve link stil dosyası URL'lerini otomatik yükler.
Saldırganlar bu açığı kullanarak sunucu tarafında rastgele iç veya bulut uç noktalarına istek gönderebilir ve gizli yanıtları ifşa edebilir.
Show the technical text from the sources
Happy DOM is a JavaScript implementation of a web browser without its graphical user interface. Prior to 21.0.0, Happy DOM loads iframe src URLs and link rel="stylesheet" href URLs by default while parsing untrusted HTML on the server because disableIframePageLoading and disableCSSFileLoading default to false. An attacker who controls parsed HTML can therefore cause server-side requests to arbitrary internal or cloud endpoints without an application opt-in and may expose confidential responses or credentials returned by those endpoints. This issue is fixed in version 21.0.0.
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
CWE: CWE-918
This explanation was compiled automatically from the source records. Scores, active exploitation, patch and exploit status come straight from the sources.
IMPACT: Affected Products and Software
RED HAT CSAF/VEX: Product Impact Check
SCORING: CVSS from Multiple Sources
CVSS Scores
The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.
| SCORE | VERSION | SEVERITY | VECTOR | SOURCE |
|---|---|---|---|---|
| 8.6 | CVSS V31 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N | NVD |
| 8.6 | CVSS 3.x | — | Vector not published | GitHub Advisory |
| 8.6 | CVSS V3_1 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N | CVE CNA |
| 0.0 | CVSS 4.0 | — | Vector not published | GitHub Advisory |
Patch and Remediation Guide
Solution & Remediation Advisory
İncelenen resmî kaynaklarda yama durumu doğrulanamadı. Bu sonuç “yama yok” anlamına gelmez.
Public exploit and active exploitation status
Verified exploit intelligence
No verified public PoC, exploit repository or Metasploit module has been found for this CVE yet.
Weakness Classification and Attack Patterns (CWE & CAPEC)
CWE - Common Weakness Enumeration
While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-118660 is associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-118660 weaknesses.
Attack Vector and Accessibility
Official Sources and Advisories
CVSS Vector Radar Chart
8.6 / 10Vulnerability Scoring Details
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:NYama durumu bilinmiyor
Weakness Type (CWE & CAPEC)
Similar Vulnerabilities
Get this vulnerability through the API
Affected products, version ranges, exploitation status and patch information in a single request, with a free key.
curl -H "x-api-key: $DAYBREACH_API_KEY" \ "https://api.daybreach.dev/api/v1/intel/cves/CVE-2026-118660"