CVEvulnerability

CVE-2026-66843

2.3 LOW Published 2026-08-06 Modified 2026-10-24 Official page ↗
Status
Modified
Published
2026-08-06
Last modified
2026-10-24
Assigner
6b3ad84c-e1a6-4bf7-a703-f496b71e49db
CVSS 4.0 (6b3ad84c-e1a6-4bf7-a703-f496b71e49db)
2.3 LOW — 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
CVSS 3.1 ([email protected])
6.1 MEDIUM — CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Weaknesses
CWE-829

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 1.4.5 and from 1.5.0-rc.0 before 1.5.3.

Affected configurations

• rrrene htmlsanitizeex (>= 0.3.1 < 1.5.3)

Related

Weakness · CWE (1)

  • CWE-829 Inclusion of Functionality from Untrusted Control Sphere weakness

References