CVE-2020-26237 – Prototype Pollution in highlight.js

https://notcve.org/view.php?id=CVE-2020-26237

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. • https://github.com/highlightjs/highlight.js/commit/7241013ae011a585983e176ddc0489a7a52f6bb0 https://github.com/highlightjs/highlight.js/pull/2636 https://github.com/highlightjs/highlight.js/security/advisories/GHSA-vfrc-7r7c-w9mx https://lists.debian.org/debian-lts-announce/2020/12/msg00041.html https://www.npmjs.com/package/highlight.js https://www.oracle.com/security-alerts/cpujul2022.html https://access.redhat.com/security/cve/CVE-2020-26237 https://bugzilla.redhat.com/show_bug.cgi?id=1901662 • CWE-20: Improper Input Validation CWE-471: Modification of Assumed-Immutable Data (MAID) •