Answer in brief
CVE-2026-104477 records a Medium severity (CVSS 5.3) vulnerability in Showdown through 2.1.0 XSS via unescaped quote in href and src attributes. The current sources do not mark it as known exploited. The current feed maps showdownjs/showdown (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 5.3. 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 showdownjs/showdown (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| showdownjs/showdowngeneric | >=0 <=2.1.0 | Not reported |
Published upstream
Oct 2, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 2, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 2, 2026
Showdown through 2.1.0 contains a cross-site scripting vulnerability in the makehtml link and image subparsers, which fail to escape double quotes in destination URLs placed into href and src attributes. Attackers can craft markdown links or images containing a double quote followed by onerror or onmouseover handlers to execute script when victims view rendered HTML.
Quoted source text, attributed separately from HOL analysis.