Moderate severity vulnerability that affects league/commonmark
Published Mar 24, 2019 · Updated Nov 3, 2026
Original summary
Normalized public record · Updated Nov 3, 2026
Moderate severity vulnerability that affects league/commonmark
Publisher and source text is retained separately from QFinch interpretation.
QFinch assessment
## CVE-2019-10010
Potential impact
In league/commonmark 0.18.2 and below, malicious users can insert double-encoded HTML entities into their Markdown like this: This library would (correctly) unescape the & entity to & during the parsing step. However, the renderer step would fail to properly re-escape the resulting : string, thus producing the following malicious HTML output: Browsers would interpret : as a : character and allow the JS to be executed when the link is clicked. This vulnerability was present in the upstream library this project was forked from and therefore exists in all prior versions of league/commonmark.
Evidence: public source recordsAffected products
| Affected package, product or range | Fix status |
|---|---|
| Consult the referenced vendor advisory for affected versions. | Consult source advisory |
Matching a version is only one part of assessing exposure. QFinch has not assessed your environment on this public page.
Remediation
Apply the vendor-supported fixed release or mitigation, then verify the affected component is no longer reachable.
- Confirm the affected product and reachable code path exist in your environment.
- Apply the vendor-supported patch or mitigation from the primary advisory.
- Rescan the exact deployed revision and retain verification evidence.
Evidence coverage
- SSVC priority
- LOW
- Confidence
- Not available
- Aliases
- None reported
Scores appear only when corresponding evidence exists. Missing data is never interpreted as zero risk.
Sources and record history
Record history
Published Mar 24, 2019 · Last refreshed Nov 3, 2026