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Case File

CVE-2021-29503

HIGH · CVSS 8.1 EPSS 1.04% Public Exploit

Source: NVD + CISA KEV + EPSS (historical backfill) · Published 2021-05-19 · Last synced 2026-08-04

CyberRota Analysis

This is a high severity vulnerability with a CVSS score of 8.1. It affects Java. Public exploit code or proof-of-concept references have been detected in its references. Exploitation may require the attacker to be authenticated.

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-2021-29503
Severity
HIGH
CVSS
8.1
EPSS
1.04%
Java

Original NVD Description

HedgeDoc is a platform to write and share markdown. HedgeDoc before version 1.8.2 is vulnerable to a cross-site scripting attack using the YAML-metadata of a note. An attacker with write access to a note can embed HTML tags in the Open Graph metadata section of the note, resulting in the frontend rendering the script tag as part of the `<head>` section. Unless your instance prevents guests from editing notes, this vulnerability allows unauthenticated attackers to inject JavaScript into notes that allow guest edits. If your instance prevents guests from editing notes, this vulnerability allows authenticated attackers to inject JavaScript into any note pages they have write-access to. This vulnerability is patched in version 1.8.2. As a workaround, one can disable guest edits until the next update.

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