CVE-2026-66829 (GCVE-0-2026-66829)

Vulnerability from cvelistv5 – Published: 2026-08-06 14:49 – Updated: 2026-08-06 15:42
VLAI
Title
html_sanitize_ex HTML5 scrubber keeps attacker-supplied meta refresh, allowing forced cross-origin redirection
Summary
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.
Severity
2.3 (Low)
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
  • CWE-601 - URL Redirection to Untrusted Site ('Open Redirect')
Assigner
EEF
References
Impacted products
Vendor Product Version
rrrene html_sanitize_ex Affected: 0.3.1 , < 1.5.3 (semver)
    cpe:2.3:a:rrrene:html_sanitize_ex:*:*:*:*:*:*:*:*
 Create a notification for this product.
rrrene html_sanitize_ex Affected: 8976d64ea0b77d26093a94a43ec48a3978e8d028 , < 9f7e38be51edc38f132dfe994f37af5cf5e0e76f (git)
    cpe:2.3:a:rrrene:html_sanitize_ex:*:*:*:*:*:*:*:*
 Create a notification for this product.
Credits
Peter Ullrich Jonatan Männchen / EEF René Föhring
Show details on NVD website
To clipboard 

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                "timestamp": "2026-08-06T15:42:40.366099Z",
                "version": "2.0.3"
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    "dateReserved": "2026-08-06T08:15:02.719Z",
    "dateUpdated": "2026-08-06T15:42:46.200Z",
    "state": "PUBLISHED"
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  "vulnerability-lookup:meta": {
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      "date": "2026-08-08",
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}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.