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 1.5.3.
References
| Link | Resource |
|---|---|
| https://cna.erlef.org/cves/CVE-2026-66829.html | Patch Third Party Advisory |
| 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
History
11 Aug 2026, 13:51
| Type | Values Removed | Values Added |
|---|---|---|
| References | () https://cna.erlef.org/cves/CVE-2026-66829.html - Patch, Third Party Advisory | |
| References | () https://github.com/rrrene/html_sanitize_ex/commit/9f7e38be51edc38f132dfe994f37af5cf5e0e76f - Patch | |
| References | () https://github.com/rrrene/html_sanitize_ex/security/advisories/GHSA-2c6f-3j54-xpcr - Broken Link | |
| References | () https://osv.dev/vulnerability/EEF-CVE-2026-66829 - Patch, Third Party Advisory | |
| CPE | cpe:2.3:a:rrrene:htmlsanitizeex:*:*:*:*:*:*:*:* | |
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 6.1 |
| First Time |
Rrrene
Rrrene htmlsanitizeex |
06 Aug 2026, 16:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-08-06 16:16
Updated : 2026-08-11 13:51
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')
