CVEvulnerability
CVE-2020-26237
8.7 HIGH
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
- https://github.com/highlightjs/highlight.js/commit/7241013ae011a585983e176ddc0489a7a52f6bb0 Patch, Third Party Advisory
- https://github.com/highlightjs/highlight.js/pull/2636 Patch, Third Party Advisory
- https://github.com/highlightjs/highlight.js/security/advisories/GHSA-vfrc-7r7c-w9mx Mitigation, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2020/12/msg00041.html Mailing List, Third Party Advisory
- https://www.npmjs.com/package/highlight.js Third Party Advisory
- https://www.oracle.com/security-alerts/cpujul2022.html Third Party Advisory
- https://github.com/highlightjs/highlight.js/commit/7241013ae011a585983e176ddc0489a7a52f6bb0 Patch, Third Party Advisory
- https://github.com/highlightjs/highlight.js/pull/2636 Patch, Third Party Advisory
- https://github.com/highlightjs/highlight.js/security/advisories/GHSA-vfrc-7r7c-w9mx Mitigation, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2020/12/msg00041.html Mailing List, Third Party Advisory
- https://www.npmjs.com/package/highlight.js Third Party Advisory
- https://www.oracle.com/security-alerts/cpujul2022.html Third Party Advisory