Vulnerability Monitor

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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. 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.


Security Impact Summary

This vulnerability carries a MEDIUM severity rating with a CVSS v3.1 score of 5.8, indicating it can be exploited remotely over the network but requires specific conditions to be met though user interaction is required requiring only low-level privileges . The vulnerability impacts integrity (unauthorized modifications), for affected systems. Impacting 3 products from highlightjs, from debian, from oracle organizations running these solutions should prioritize assessment and patching.

Historical Context

Reported in 2020, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.


Published

2020-11-24T23:15:11.223

Last Modified

2024-11-21T05:19:37.197

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 5.8 (MEDIUM)

CVSSv2 Vector

AV:N/AC:M/Au:S/C:N/I:P/A:P

  • Access Vector: NETWORK
  • Access Complexity: MEDIUM
  • Authentication: SINGLE
  • Confidentiality Impact: NONE
  • Integrity Impact: PARTIAL
  • Availability Impact: PARTIAL
Exploitability Score

6.8

Impact Score

4.9

Weaknesses
  • Type: Secondary
    CWE-471

Affected Vendors & Products
Type Vendor Product Version/Range Vulnerable?
Application highlightjs highlight.js < 9.18.2 Yes
Application highlightjs highlight.js < 10.1.2 Yes
Operating System debian debian_linux 9.0 Yes
Application oracle mysql_enterprise_monitor ≤ 8.0.30 Yes

References

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For highlightjs's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.