CVEvulnerability

CVE-2020-26237

8.7 HIGH Published 2020-11-24 Modified 2026-06-17 Official page ↗
Status
Modified
Published
2020-11-24
Last modified
2026-06-17
Assigner
[email protected]
CVSS 3.1 ([email protected])
5.8 MEDIUM — CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:N/I:H/A:N
CVSS 3.1 ([email protected])
8.7 HIGH — CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:N/I:H/A:H
CVSS 2.0 ([email protected])
4.9 MEDIUM — AV:N/AC:M/Au:S/C:N/I:P/A:P
Weaknesses
CWE-471

Description

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.

Affected configurations

• highlightjs highlight.js (< 9.18.2) • highlightjs highlight.js (>= 10.1.0 < 10.1.2) • debian debian linux 9.0 • oracle mysql enterprise monitor (<= 8.0.30)

Related

Weakness · CWE (1)

  • CWE-471 Modification of Assumed-Immutable Data (MAID) weakness

References