AUGUST 4, 2026
Live Feed
Back to database
Case File

CVE-2021-43827

MEDIUM · CVSS 4.3 EPSS 0.80% Public Exploit

Source: NVD + CISA KEV + EPSS (historical backfill) · Published 2021-12-14 · Last synced 2026-08-04

CyberRota Analysis

This is a medium severity vulnerability with a CVSS score of 4.3. It affects Java. Public exploit code or proof-of-concept references have been detected in its references.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

Note: these links are listed for security research and verification purposes only.

CVE
CVE-2021-43827
Severity
MEDIUM
CVSS
4.3
EPSS
0.80%
Java

Original NVD 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.

Related CVEs

Other vulnerabilities affecting the same vendor(s)