> CVE-2026-66843 [LOW]

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PUBLISHED
2026-08-06 16:16
MODIFIED
2026-08-06 16:16
CVSS_SCORE V3
2.3
EPSS (Prob. Exploit)
0.51%
Top 57.2%
DATA SOURCES:
NVD đź”— 2026-08-06 CWE MITRE đź”— 2026-11-01 FIRST EPSS đź”— 2026-10-25 OSV đź”— 2026-08-13

> DESCRIPTION

Inclusion of Functionality from Untrusted Control Sphere vulnerability in the HTML5 scrubber in rrrene html_sanitize_ex allows a remote attacker to load a document of their choosing into a trusted page via the data attribute of an <object> element in sanitized HTML. object is the one URI-bearing element in lib/html_sanitize_ex/scrubber/html5.ex never registered through allow_tag_with_uri_attributes/3, and its only guard is a prefix match on lowercase "javascript:", so mixed-case variants, data: URIs, protocol-relative URLs and same-origin paths all survive. This is not unconditional cross-site scripting. A javascript: URL does not execute through <object data> in current browsers, data: documents load in an opaque origin, and host-origin script execution additionally requires the application to serve attacker-controlled content from a same-origin path. This issue affects html_sanitize_ex: from 0.3.1 before 1.5.3.

> AFFECTED_PRODUCTS

ℹ️ Aucun produit affecté n'a encore été publié par NVD pour cette CVE.

> CVSS V3 METRICS

CVSS_VECTOR
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

> MÉTRIQUES CVSS DÉTAILLÉES

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Métrique Valeur Interprétation
AV (Vecteur d'Attaque)
Attack Vector
Network (N)
Exploit possible à distance via réseau (HTTP, API, etc.)
AC (Complexité d'Attaque)
Attack Complexity
Low (L)
Peu de conditions requises pour exploiter
PR (Privilèges Requis)
Privileges Required
None (N)
Aucune authentification requise
UI (Interaction Utilisateur)
User Interaction
Unknown (P)
Interaction inconnue
S (Périmètre)
Scope
Unchanged (U)
Impact reste dans le périmètre du composant compromis
C (Impact Confidentialité)
Confidentiality Impact
None (N)
Aucune divulgation d'informations
I (Impact Intégrité)
Integrity Impact
None (N)
Aucune modification de données possible
A (Impact Disponibilité)
Availability Impact
None (N)
Aucune interruption de service

> RÉSUMÉ DES IMPACTS

Confidentialité
None
Aucune divulgation d'informations
Intégrité
None
Aucune modification de données possible
Disponibilité
None
Aucune interruption de service

> WEAKNESSES

CWE-829

> CWE DETAILED DESCRIPTIONS

CWE-829: Inclusion of Functionality from Untrusted Control Sphere - The product imports, requires, or includes executable functionality (such as a library) from a source that is outside of the intended control sphere.

> OSV (GOOGLE OPEN SOURCE VULNERABILITIES)

html_sanitize_ex HTML5 scrubber keeps attacker-supplied `<object>` elements, allowing untrusted content embedding

AFFECTED PACKAGES:
Unknown / Unknown
12 versions affected
ALIASES:
EEF-CVE-2026-66843, GHSA-xmm9-jc22-rcgj

> HISTORIQUE DES MODIFICATIONS

Première apparition
06/08/2026 16:16
Source: NVD
📊 ENRICHISSEMENT 01/09/2026 06:02
CWE
Champ modifié: Description CWE
Ancienne valeur:
N/A
Nouvelle valeur:
CWE-829: Inclusion of Functionality from Untrusted Control Sphere - The product imports, requires, or includes executable functionality (such as a library) from a source that is outside of the intende...
Total des modifications: 1 Dernière mise à jour: 2 months ago

> REFERENCES

https://cna.erlef.org/cves/CVE-2026-66843.html
https://github.com/rrrene/html_sanitize_ex/commit/bec27fec4de99e40c68c4285a610e0...
https://github.com/rrrene/html_sanitize_ex/security/advisories/GHSA-xmm9-jc22-rc...
https://osv.dev/vulnerability/EEF-CVE-2026-66843
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