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CVE-2020-26237GHSA-VFRC-7R7C-W9MX

Prototype Pollution in highlight.js

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 9.18.2, 10.1.2
None on Exploit-DB, Metasploit or GitHub

Summary

Highlight.js is a syntax highlighter written in JavaScript. Highlight.js versions before 9.18.2 and 10.1.2 are vulnerable to Prototype Pollution. A malicious HTML code block can be crafted that will result in prototype pollution of the base object's prototype during highlighting. If you allow users to insert custom HTML code blocks into your page/app via parsing Markdown code blocks (or similar) and do not filter the language names the user can provide you may be vulnerable. The pollution should just be harmless data but this can cause problems for applications not expecting these properties to exist and can result in strange behavior or application crashes, i.e. a potential DOS vector. If your website or application does not render user provided data it should be unaffected. Versions 9.18.2 and 10.1.2 and newer include fixes for this vulnerability. If you are using version 7 or 8 you are encouraged to upgrade to a newer release.

Timeline

  1. CVE published
  2. Record last updated

Affected versions

  • highlightjs highlight.js

    fixed in 9.18.2; From 10.0.0 · fixed in 10.1.2

  • highlight.jsnpm

    fixed in 9.18.2

  • highlight.jsnpm

    From 10.0.0 · fixed in 10.1.2

References 6

GitHub · highlightjs/highlight.js

npmjs.com

lists.debian.org

oracle.com