cvedb.io
CVE-2021-43827
MEDIUM · CVSS 4.3
EPSS exploitation probability: 0%
Published 2021-12-14T23:15:08.020 · Last modified 2026-06-17T04:11:31.367

Summary

discourse-footnote is a library providing footnotes for posts in Discourse. ### Impact When posting an inline footnote wrapped in `<a>` tags (e.g. `<a>^[footnote]</a>`, the resulting rendered HTML would include a nested `<a>`, which is stripped by Nokogiri because it is not valid. This then caused a javascript error on topic pages because we were looking for an `<a>` element inside the footnote reference span and getting its ID, and because it did not exist we got a null reference error in javascript. Users are advised to update to version 0.2. As a workaround editing offending posts from the rails console or the database console for self-hosters, or disabling the plugin in the admin panel can mitigate this issue.

Affected products

discourse — discourse_footnote

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.