VDB

CVE-2020-26237

CVE-2020-26237 PUBLISHED

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.

EPSS 0.60% · 69.9th percentile

Risk Scores

EPSS Score
0.60%
69.9th percentile

Affected Products

VendorProductVersions
Ubuntu:25.10highlight.js9.18.5+dfsg1-2, 0
Ubuntu:22.04:LTShighlight.js9.18.5+dfsg1-1, 0
Ubuntu:20.04:LTShighlight.js*, 9.12.0+dfsg1-4ubuntu1, 0
Ubuntu:18.04:LTShighlight.js0, 9.12.0+dfsg1-3, 9.12.0+dfsg1-4
Ubuntu:16.04:LTShighlight.js0, 8.2+ds-4build1
Ubuntu:24.04:LTShighlight.js*, 0

Timeline

  • Nov 24, 2020 CVE Published
  • Dec 31, 2020 CVE Updated
  • Apr 14, 2021 EPSS Score
  • Jun 23, 2021 EPSS Score
  • Aug 24, 2021 EPSS Score
  • Oct 26, 2021 EPSS Score
  • Jan 6, 2022 EPSS Score
  • Feb 4, 2022 EPSS Score
  • Feb 28, 2022 EPSS Score
  • Apr 1, 2022 EPSS Score
  • May 1, 2022 EPSS Score
  • Jul 3, 2022 EPSS Score
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