CVE-2026-66829

URL Redirection to Untrusted Site ('Open Redirect') vulnerability in the HTML5 scrubber in rrrene html_sanitize_ex allows a remote attacker to force visitors of a page to navigate to a site of the attacker's choosing via a <meta http-equiv="refresh"> element in sanitized HTML. HtmlSanitizeEx.html5/1 keeps attacker-supplied <meta> elements in its output. A meta element acts on the whole document rather than on the fragment it was embedded in, so it can also declare document-wide directives such as Content-Security-Policy. This is not cross-site scripting. Browsers do not navigate a meta refresh to a javascript: URL, so the uppercase JAVASCRIPT: filter bypass yields no script execution and none was demonstrated. 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.

CVSS v3 6.1 MEDIUM

6.1^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 2.7

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact NONE

Scope CHANGED

References

Link	Resource
https://cna.erlef.org/cves/CVE-2026-66829.html	Patch Third Party Advisory
https://github.com/rrrene/html_sanitize_ex/commit/29454dc99513fd9b5b6429ab7b6695ad09889227
https://github.com/rrrene/html_sanitize_ex/commit/9f7e38be51edc38f132dfe994f37af5cf5e0e76f	Patch
https://github.com/rrrene/html_sanitize_ex/security/advisories/GHSA-2c6f-3j54-xpcr	Broken Link
https://osv.dev/vulnerability/EEF-CVE-2026-66829	Patch Third Party Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:rrrene:htmlsanitizeex:*:*:*:*:*:*:*:*

History

No history.

Information

Published : 2026-08-06 16:16

Updated : 2026-08-19 12:18

NVD link : CVE-2026-66829

Mitre link : CVE-2026-66829

CVE.ORG link : CVE-2026-66829

JSON object : View

Products Affected

rrrene

htmlsanitizeex

CWE

CWE-601

URL Redirection to Untrusted Site ('Open Redirect')

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