Answer in brief
CVE-2026-66829 records a Low severity (CVSS 2.3) vulnerability in html_sanitize_ex HTML5 scrubber keeps attacker-supplied meta refresh, allowing forced cross-origin redirection. The current sources do not mark it as known exploited. The current feed maps rrrene/html_sanitize_ex (generic), rrrene/html_sanitize_ex (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 2.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps rrrene/html_sanitize_ex (generic), rrrene/html_sanitize_ex (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| rrrene/html_sanitize_exgeneric | >=0.3.1 <1.5.3 | 1.5.3 |
| rrrene/html_sanitize_exgeneric | >=8976d64ea0b77d26093a94a43ec48a3978e8d028 <9f7e38be51edc38f132dfe994f37af5cf5e0e76f | 9f7e38be51edc38f132dfe994f37af5cf5e0e76f |
Published upstream
Aug 6, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 6, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 6, 2026
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.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2026-66829 records a Low severity (CVSS 2.3) vulnerability in html_sanitize_ex HTML5 scrubber keeps attacker-supplied meta refresh, allowing forced cross-origin redirection. The current sources do not mark it as known exploited. The current feed maps rrrene/html_sanitize_ex (generic), rrrene/html_sanitize_ex (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 2.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps rrrene/html_sanitize_ex (generic), rrrene/html_sanitize_ex (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| rrrene/html_sanitize_exgeneric | >=0.3.1 <1.5.3 | 1.5.3 |
| rrrene/html_sanitize_exgeneric | >=8976d64ea0b77d26093a94a43ec48a3978e8d028 <9f7e38be51edc38f132dfe994f37af5cf5e0e76f | 9f7e38be51edc38f132dfe994f37af5cf5e0e76f |
Published upstream
Aug 6, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 6, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 6, 2026
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.
Quoted source text, attributed separately from HOL analysis.