Answer in brief
CVE-2026-8445 records a Critical severity (CVSS 9.8) vulnerability in justhtml before 1.12.0 Sanitizer Bypass via Markdown. The current sources do not mark it as known exploited. The current feed maps EmilStenstrom/justhtml (generic), justhtml (pypi). 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 9.8. 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 EmilStenstrom/justhtml (generic), justhtml (pypi). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| EmilStenstrom/justhtmlgeneric | >=0 <1.12.0 | 1.12.0 |
| justhtmlpypi | >=0 <1.12.0 | 1.12.0 |
Published upstream
Aug 23, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 26, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 7, 2026
justhtml versions <= 1.11.0 (fixed in 1.12.0) do not sufficiently escape HTML-significant characters (angle brackets) in text nodes when converting a parsed document to Markdown via to_markdown(). While a small set of Markdown metacharacters are escaped, characters such as < and > are preserved, so untrusted input that is safe in to_html() — including entity-decoded text (e.g. <script>) or text from RCDATA/RAWTEXT-parsed elements like <title>, <textarea>, <noscript>, and <plaintext> — can be emitted as raw HTML in the Markdown output, enabling a sanitizer bypass and potential cross-site scripting when that output is rendered.
Quoted source text, attributed separately from HOL analysis.