CVEvulnerability

CVE-2021-43827

4.3 MEDIUM Published 2021-12-14 Modified 2026-06-17 Official page ↗
Status
Modified
Published
2021-12-14
Last modified
2026-06-17
Assigner
[email protected]
CVSS 3.1 ([email protected])
4.3 MEDIUM — CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
CVSS 2.0 ([email protected])
4.0 MEDIUM — AV:N/AC:L/Au:S/C:N/I:N/A:P
Weaknesses
CWE-755

Description

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 configurations

• discourse discourse footnote (< 0.2)

Related

Weakness · CWE (1)

  • CWE-755 Improper Handling of Exceptional Conditions weakness

References